diff --git a/crates/diffguard-analytics/src/lib.rs b/crates/diffguard-analytics/src/lib.rs
index 79dbd701..a4c9ed52 100644
--- a/crates/diffguard-analytics/src/lib.rs
+++ b/crates/diffguard-analytics/src/lib.rs
@@ -175,7 +175,7 @@ pub struct TrendRun {
     /// Stored as `u64` to avoid silent truncation for very large repositories
     /// (those with more than 2^32 - 1 unique files).
     pub files_scanned: u64,
-    pub lines_scanned: u32,
+    pub lines_scanned: u64,
     pub findings: u32,
 }
 
diff --git a/crates/diffguard-core/src/render.rs b/crates/diffguard-core/src/render.rs
index 075ea226..31c0aa1e 100644
--- a/crates/diffguard-core/src/render.rs
+++ b/crates/diffguard-core/src/render.rs
@@ -1,6 +1,6 @@
 use diffguard_types::{
     CheckReceipt, Finding, REASON_GIT_UNAVAILABLE, REASON_MISSING_BASE, REASON_NO_DIFF_INPUT,
-    REASON_TOOL_ERROR, REASON_TRUNCATED, VerdictStatus,
+    REASON_TOOL_ERROR, REASON_TRUNCATED, VerdictStatus, escape_md,
 };
 
 /// Reasons that are meaningful to render in markdown output.
@@ -114,28 +114,6 @@ fn render_finding_row(f: &Finding) -> String {
     )
 }
 
-/// Escapes special Markdown characters in table cell content.
-///
-/// Escapes pipe (`|`), backtick (`` ` ``), hash (`#`), asterisk (`*`),
-/// underscore (`_`), open bracket (`[`), close bracket (`]`), and greater-than
-/// (`>`) characters by prefixing with backslash. Also escapes CRLF (`\r\n`)
-/// and LF (`\n`) line endings to prevent breaking the markdown table structure.
-///
-/// These escapes are needed to prevent breaking the markdown table structure
-/// and prevent unintended markdown formatting.
-fn escape_md(s: &str) -> String {
-    s.replace('|', "\\|")
-        .replace('`', "\\`")
-        .replace('#', "\\#")
-        .replace('*', "\\*")
-        .replace('_', "\\_")
-        .replace('[', "\\[")
-        .replace(']', "\\]")
-        .replace('>', "\\>")
-        .replace('\r', "\\r")
-        .replace('\n', "\\n")
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_common_escapes.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_common_escapes.snap
new file mode 100644
index 00000000..9e6445bd
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_common_escapes.snap
@@ -0,0 +1,6 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"dir\\ name\\\"quote\\\"\\\\tab\\tnewline\\ncarriage\\rend\"#)"
+---
+dir name"quote"\tab	newline
+carriage
end
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_embedded_octal-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_embedded_octal-2.snap
new file mode 100644
index 00000000..dc5ca10a
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_embedded_octal-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"octal\\141\\040space\"#)"
+---
+octala space
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_embedded_octal.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_embedded_octal.snap
new file mode 100644
index 00000000..8deade1a
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_embedded_octal.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"hello\\041world\"#)"
+---
+hello!world
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_empty.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_empty.snap
new file mode 100644
index 00000000..b3ff7320
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_empty.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(\"\")"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_max_octal_values-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_max_octal_values-2.snap
new file mode 100644
index 00000000..0b978dab
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_max_octal_values-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\77\"#)"
+---
+?
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_max_octal_values.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_max_octal_values.snap
new file mode 100644
index 00000000..1e6c3b04
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_max_octal_values.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\377\"#)"
+---
+�
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_multiple_octal.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_multiple_octal.snap
new file mode 100644
index 00000000..ea66aec9
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_multiple_octal.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\001\\002\\003\"#)"
+---
+

diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_no_escapes.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_no_escapes.snap
new file mode 100644
index 00000000..9fc9a316
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_no_escapes.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(\"plain_string_no_escapes\")"
+---
+plain_string_no_escapes
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_non_octal_digits-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_non_octal_digits-2.snap
new file mode 100644
index 00000000..200f6401
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_non_octal_digits-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\9\"#)"
+---
+\9
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_non_octal_digits.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_non_octal_digits.snap
new file mode 100644
index 00000000..c7b2a0ac
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_non_octal_digits.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\8\"#)"
+---
+\8
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-2.snap
new file mode 100644
index 00000000..e716ed5c
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\1\"#)"
+---
+

diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-3.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-3.snap
new file mode 100644
index 00000000..d98a7567
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-3.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\2\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-4.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-4.snap
new file mode 100644
index 00000000..442b0033
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-4.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\3\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-5.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-5.snap
new file mode 100644
index 00000000..5ae62c76
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-5.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\4\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-6.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-6.snap
new file mode 100644
index 00000000..fd7db8ec
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-6.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\5\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-7.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-7.snap
new file mode 100644
index 00000000..d9e2d5ff
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-7.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\6\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-8.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-8.snap
new file mode 100644
index 00000000..56582832
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal-8.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\7\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal.snap
new file mode 100644
index 00000000..a4d987e5
Binary files /dev/null and b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_single_digit_octal.snap differ
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_three_digit_octal-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_three_digit_octal-2.snap
new file mode 100644
index 00000000..c167f6cf
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_three_digit_octal-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\177\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_three_digit_octal.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_three_digit_octal.snap
new file mode 100644
index 00000000..a8436823
Binary files /dev/null and b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_three_digit_octal.snap differ
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_trailing_backslash.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_trailing_backslash.snap
new file mode 100644
index 00000000..5c5346ac
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_trailing_backslash.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"endswith\\\"#)"
+---
+endswith\
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-2.snap
new file mode 100644
index 00000000..e7b8b0d0
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\07\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-3.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-3.snap
new file mode 100644
index 00000000..af6652ec
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-3.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\10\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-4.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-4.snap
new file mode 100644
index 00000000..c7033a06
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-4.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\12\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-5.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-5.snap
new file mode 100644
index 00000000..351fb4aa
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-5.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\15\"#)"
+---
+
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-6.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-6.snap
new file mode 100644
index 00000000..0b978dab
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal-6.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\77\"#)"
+---
+?
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal.snap
new file mode 100644
index 00000000..0e2be016
Binary files /dev/null and b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_two_digit_octal.snap differ
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_unknown_escape-2.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_unknown_escape-2.snap
new file mode 100644
index 00000000..ce8a4a48
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_unknown_escape-2.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\q1\"#)"
+---
+\q1
diff --git a/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_unknown_escape.snap b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_unknown_escape.snap
new file mode 100644
index 00000000..dc6a4ec4
--- /dev/null
+++ b/crates/diffguard-diff/src/snapshots/diffguard_diff__unified__tests__snapshot_unescape_git_path_unknown_escape.snap
@@ -0,0 +1,5 @@
+---
+source: crates/diffguard-diff/src/unified.rs
+expression: "unescape_git_path(r#\"\\q\"#)"
+---
+\q
diff --git a/crates/diffguard-diff/tests/integration_octal_escaped_paths.rs b/crates/diffguard-diff/tests/integration_octal_escaped_paths.rs
new file mode 100644
index 00000000..f2b1055a
--- /dev/null
+++ b/crates/diffguard-diff/tests/integration_octal_escaped_paths.rs
@@ -0,0 +1,147 @@
+//! Integration tests for parsing diffs with octal-escaped paths.
+//!
+//! These tests exercise the full pipeline: raw diff text with quoted paths
+//! containing octal escape sequences → parse_unified_diff → DiffLine with
+//! correctly unescaped paths.
+//!
+//! The change being tested: replacing `u8 as u32` with `u32::from(u8)` in
+//! unescape_git_path's octal parsing branch. This is a lossless widening cast
+//! that doesn't affect behavior, but these tests verify the full integration
+//! path still works correctly.
+
+use diffguard_diff::parse_unified_diff;
+use diffguard_types::Scope;
+
+/// Test: Full pipeline with a path containing an octal-escaped space.
+/// Git outputs paths with spaces as `\040` (octal for space).
+///
+/// Flow: diff text with quoted path → parse_diff_git_line → tokenize_git_paths
+///       → unquote_git_token → unescape_git_path → unescaped path in DiffLine
+#[test]
+fn test_parse_diff_with_octal_escaped_space_in_path() {
+    // Git quotes paths with special characters and uses octal escapes for spaces
+    // "\040" is octal for space (ASCII 32)
+    let diff = r#"
+diff --git "a/path\040with spaces/file.rs" "b/path with spaces/file.rs"
+--- "a/path\040with spaces/file.rs"
++++ "b/path with spaces/file.rs"
+@@ -1 +1,2 @@
+ fn existing() {}
++fn added() {}
+"#;
+
+    let (lines, stats) = parse_unified_diff(diff, Scope::Added).unwrap();
+
+    // The path should be unescaped: \040 → ' '
+    assert_eq!(lines.len(), 1);
+    assert_eq!(lines[0].path, "path with spaces/file.rs");
+    assert_eq!(lines[0].content, "fn added() {}");
+    assert_eq!(stats.files, 1);
+    assert_eq!(stats.lines, 1);
+}
+
+/// Test: Full pipeline with embedded octal escapes in path.
+/// Path contains multiple octal escapes representing different characters.
+///
+/// \041 = '!' (ASCII 33)
+/// \040 = ' ' (ASCII 32)
+#[test]
+fn test_parse_diff_with_multiple_octal_escapes_in_path() {
+    let diff = r#"
+diff --git "a/file\041name\040here.rs" "b/file!name here.rs"
+--- "a/file\041name\040here.rs"
++++ "b/file!name here.rs"
+@@ -1 +1,2 @@
+ fn existing() {}
++fn added() {}
+"#;
+
+    let (lines, _stats) = parse_unified_diff(diff, Scope::Added).unwrap();
+
+    // All octal escapes should be properly decoded
+    assert_eq!(lines[0].path, "file!name here.rs");
+}
+
+/// Test: Octal escapes at path boundaries (start, middle, end).
+///
+/// \143 = 'c' (ASCII 99) - octal for lowercase 'c'
+#[test]
+fn test_parse_diff_with_octal_escape_at_path_boundaries() {
+    // \143 = 'c'
+    let diff = r#"
+diff --git "a/\143at.rs" "b/cat.rs"
+--- "a/\143at.rs"
++++ "b/cat.rs"
+@@ -1 +1,2 @@
+ fn existing() {}
++fn added() {}
+"#;
+
+    let (lines, _stats) = parse_unified_diff(diff, Scope::Added).unwrap();
+    assert_eq!(lines[0].path, "cat.rs");
+}
+
+/// Test: Three-digit octal escape at maximum value.
+/// \177 = DEL (ASCII 127), \000 = NUL (ASCII 0)
+#[test]
+fn test_parse_diff_with_octal_edge_cases() {
+    // \177 = 127 (DEL), \000 = 0 (NUL)
+    // These are boundary cases for the u8→u32 cast
+    let diff = r#"
+diff --git "a/\177\000file.rs" "b/\177\000file.rs"
+--- "a/\177\000file.rs"
++++ "b/\177\000file.rs"
+@@ -1 +1,2 @@
+ fn existing() {}
++fn added() {}
+"#;
+
+    let (lines, _stats) = parse_unified_diff(diff, Scope::Added).unwrap();
+    // The path should contain the raw bytes (non-printable but valid)
+    assert_eq!(lines[0].path, "\x7F\x00file.rs");
+}
+
+/// Test: Renamed file with octal-escaped path.
+/// When a file is renamed, the "rename to" path can also have octal escapes.
+#[test]
+fn test_parse_diff_rename_with_octal_escaped_path() {
+    let diff = r#"
+diff --git "a/old\040name.rs" "b/new\040name.rs"
+rename from old name.rs
+rename to new name.rs
+--- "a/old\040name.rs"
++++ "b/new\040name.rs"
+@@ -1 +1,2 @@
+ fn existing() {}
++fn added() {}
+"#;
+
+    let (lines, _stats) = parse_unified_diff(diff, Scope::Added).unwrap();
+    // The path should be unescaped
+    assert_eq!(lines[0].path, "new name.rs");
+}
+
+/// Test: Multiple files with mixed quoted/unquoted paths.
+#[test]
+fn test_parse_diff_multiple_files_mixed_path_formats() {
+    let diff = r#"
+diff --git "a/quoted\040path.rs" "b/quoted path.rs"
+--- "a/quoted\040path.rs"
++++ "b/quoted path.rs"
+@@ -1 +1,2 @@
++added to quoted path
+diff --git a/normal_path.rs b/normal_path.rs
+--- a/normal_path.rs
++++ b/normal_path.rs
+@@ -1 +1,2 @@
++added to normal path
+"#;
+
+    let (lines, stats) = parse_unified_diff(diff, Scope::Added).unwrap();
+
+    assert_eq!(lines.len(), 2);
+    assert_eq!(lines[0].path, "quoted path.rs");
+    assert_eq!(lines[1].path, "normal_path.rs");
+    assert_eq!(stats.files, 2);
+    assert_eq!(stats.lines, 2);
+}
diff --git a/crates/diffguard-domain/src/evaluate.rs b/crates/diffguard-domain/src/evaluate.rs
index d999bc12..0273f773 100644
--- a/crates/diffguard-domain/src/evaluate.rs
+++ b/crates/diffguard-domain/src/evaluate.rs
@@ -26,7 +26,7 @@ pub struct Evaluation {
     /// The previous `u32` cast would silently truncate, producing incorrect
     /// (often zero) counts for very large codebases.
     pub files_scanned: u64,
-    pub lines_scanned: u32,
+    pub lines_scanned: u64,
     /// Aggregated per-rule hit counts (deterministically sorted by rule ID).
     pub rule_hits: Vec<RuleHitStat>,
 }
@@ -102,7 +102,7 @@ pub fn evaluate_lines_with_overrides_and_language(
         .iter()
         .map(|line| line.path.clone())
         .collect::<BTreeSet<_>>();
-    let lines_scanned = u32::try_from(input_lines.len()).unwrap_or(u32::MAX);
+    let lines_scanned = u64::try_from(input_lines.len()).unwrap_or(u64::MAX);
 
     let mut current_file: Option<String> = None;
     let mut current_lang = Language::Unknown;
diff --git a/crates/diffguard-domain/src/preprocess.rs b/crates/diffguard-domain/src/preprocess.rs
index cbf67d5e..1e9b34fb 100644
--- a/crates/diffguard-domain/src/preprocess.rs
+++ b/crates/diffguard-domain/src/preprocess.rs
@@ -166,6 +166,7 @@ pub struct PreprocessOptions {
 }
 
 impl PreprocessOptions {
+    #[must_use]
     pub fn none() -> Self {
         Self {
             mask_comments: false,
@@ -173,6 +174,7 @@ impl PreprocessOptions {
         }
     }
 
+    #[must_use]
     pub fn comments_only() -> Self {
         Self {
             mask_comments: true,
diff --git a/crates/diffguard-domain/tests/red_tests_work_e8a88475.rs b/crates/diffguard-domain/tests/red_tests_work_e8a88475.rs
new file mode 100644
index 00000000..e4dc5f4c
--- /dev/null
+++ b/crates/diffguard-domain/tests/red_tests_work_e8a88475.rs
@@ -0,0 +1,201 @@
+//! Red tests for work-e8a88475: #[must_use] on preprocess.rs factory/constructor methods
+//!
+//! These tests verify that `#[must_use]` attribute is present on 6 functions in
+//! `crates/diffguard-domain/src/preprocess.rs` that return `Self` values representing
+//! configuration or state that must not be silently dropped.
+//!
+//! The target functions are:
+//! 1. PreprocessOptions::none() - factory method
+//! 2. PreprocessOptions::comments_only() - factory method
+//! 3. PreprocessOptions::strings_only() - factory method
+//! 4. PreprocessOptions::comments_and_strings() - factory method
+//! 5. Preprocessor::new(opts: PreprocessOptions) -> Self - constructor
+//! 6. Preprocessor::with_language(opts: PreprocessOptions, lang: Language) -> Self - constructor
+//!
+//! ## How these tests work
+//! These tests use `include_str!` to read the source file and verify that
+//! `#[must_use]` appears immediately before each target function declaration.
+//! This is a compile-time check that ensures the attribute is present.
+//!
+//! ## Expected behavior
+//! - BEFORE fix: Tests FAIL because #[must_use] is not present on those functions
+//! - AFTER fix: Tests PASS because #[must_use] is correctly placed
+
+/// Load the preprocess.rs source file for inspection.
+/// We use include_str! to get the raw source at compile time.
+const PREPROCESS_SOURCE: &str = include_str!("../src/preprocess.rs");
+
+/// Helper to find a function declaration and verify #[must_use] appears immediately before it.
+/// Returns the line number of the function if #[must_use] is found, or None if not found.
+fn find_must_use_before_function(source: &str, fn_signature: &str) -> Option<(bool, usize)> {
+    let lines: Vec<&str> = source.lines().collect();
+
+    for (i, line) in lines.iter().enumerate() {
+        if line.contains(fn_signature) {
+            // Check if the previous non-empty line has #[must_use]
+            // We need to go back and skip empty lines and comments
+            let mut check_idx = i;
+            while check_idx > 0 {
+                check_idx -= 1;
+                let prev_line = lines[check_idx].trim();
+                if prev_line.is_empty() {
+                    continue;
+                }
+                if prev_line.starts_with("//") {
+                    continue;
+                }
+                if prev_line.starts_with("/*")
+                    || prev_line.starts_with("*/")
+                    || prev_line.starts_with("*")
+                {
+                    continue;
+                }
+                // Found a meaningful previous line
+                let has_must_use = prev_line == "#[must_use]";
+                return Some((has_must_use, i + 1)); // 1-indexed line number
+            }
+            // Function is at start of file or only preceded by comments/empty lines
+            return Some((false, i + 1));
+        }
+    }
+    None
+}
+
+/// Test that PreprocessOptions::none() has #[must_use]
+#[test]
+fn preprocess_options_none_has_must_use() {
+    let result = find_must_use_before_function(PREPROCESS_SOURCE, "pub fn none() -> Self");
+    assert!(
+        result.is_some(),
+        "Could not find 'pub fn none() -> Self' in preprocess.rs"
+    );
+
+    let (has_must_use, line_num) = result.unwrap();
+    assert!(
+        has_must_use,
+        "PreprocessOptions::none() at line {} does NOT have #[must_use] attribute. \
+         The function returns Self representing configuration that must not be dropped. \
+         Expected #[must_use] to appear on the line immediately before the function declaration.",
+        line_num
+    );
+}
+
+/// Test that PreprocessOptions::comments_only() has #[must_use]
+#[test]
+fn preprocess_options_comments_only_has_must_use() {
+    let result = find_must_use_before_function(PREPROCESS_SOURCE, "pub fn comments_only() -> Self");
+    assert!(
+        result.is_some(),
+        "Could not find 'pub fn comments_only() -> Self' in preprocess.rs"
+    );
+
+    let (has_must_use, line_num) = result.unwrap();
+    assert!(
+        has_must_use,
+        "PreprocessOptions::comments_only() at line {} does NOT have #[must_use] attribute. \
+         The function returns Self representing configuration that must not be dropped. \
+         Expected #[must_use] to appear on the line immediately before the function declaration.",
+        line_num
+    );
+}
+
+/// Test that PreprocessOptions::strings_only() has #[must_use]
+#[test]
+fn preprocess_options_strings_only_has_must_use() {
+    let result = find_must_use_before_function(PREPROCESS_SOURCE, "pub fn strings_only() -> Self");
+    assert!(
+        result.is_some(),
+        "Could not find 'pub fn strings_only() -> Self' in preprocess.rs"
+    );
+
+    let (has_must_use, line_num) = result.unwrap();
+    assert!(
+        has_must_use,
+        "PreprocessOptions::strings_only() at line {} does NOT have #[must_use] attribute. \
+         The function returns Self representing configuration that must not be dropped. \
+         Expected #[must_use] to appear on the line immediately before the function declaration.",
+        line_num
+    );
+}
+
+/// Test that PreprocessOptions::comments_and_strings() has #[must_use]
+#[test]
+fn preprocess_options_comments_and_strings_has_must_use() {
+    let result =
+        find_must_use_before_function(PREPROCESS_SOURCE, "pub fn comments_and_strings() -> Self");
+    assert!(
+        result.is_some(),
+        "Could not find 'pub fn comments_and_strings() -> Self' in preprocess.rs"
+    );
+
+    let (has_must_use, line_num) = result.unwrap();
+    assert!(
+        has_must_use,
+        "PreprocessOptions::comments_and_strings() at line {} does NOT have #[must_use] attribute. \
+         The function returns Self representing configuration that must not be dropped. \
+         Expected #[must_use] to appear on the line immediately before the function declaration.",
+        line_num
+    );
+}
+
+/// Test that Preprocessor::new() has #[must_use]
+#[test]
+fn preprocessor_new_has_must_use() {
+    let result = find_must_use_before_function(
+        PREPROCESS_SOURCE,
+        "pub fn new(opts: PreprocessOptions) -> Self",
+    );
+    assert!(
+        result.is_some(),
+        "Could not find 'pub fn new(opts: PreprocessOptions) -> Self' in preprocess.rs"
+    );
+
+    let (has_must_use, line_num) = result.unwrap();
+    assert!(
+        has_must_use,
+        "Preprocessor::new() at line {} does NOT have #[must_use] attribute. \
+         The function returns Self representing preprocessor state that must not be dropped. \
+         Expected #[must_use] to appear on the line immediately before the function declaration.",
+        line_num
+    );
+}
+
+/// Test that Preprocessor::with_language() has #[must_use]
+#[test]
+fn preprocessor_with_language_has_must_use() {
+    let result = find_must_use_before_function(
+        PREPROCESS_SOURCE,
+        "pub fn with_language(opts: PreprocessOptions, lang: Language) -> Self",
+    );
+    assert!(
+        result.is_some(),
+        "Could not find 'pub fn with_language(opts: PreprocessOptions, lang: Language) -> Self' in preprocess.rs"
+    );
+
+    let (has_must_use, line_num) = result.unwrap();
+    assert!(
+        has_must_use,
+        "Preprocessor::with_language() at line {} does NOT have #[must_use] attribute. \
+         The function returns Self representing preprocessor state that must not be dropped. \
+         Expected #[must_use] to appear on the line immediately before the function declaration.",
+        line_num
+    );
+}
+
+/// Verification test: Ensure there are exactly 6 #[must_use] attributes in preprocess.rs
+/// This verifies scope is limited to the 6 specified functions and no more are added.
+#[test]
+fn exactly_six_must_use_attributes_in_preprocess() {
+    let must_use_count = PREPROCESS_SOURCE
+        .lines()
+        .filter(|line| line.trim() == "#[must_use]")
+        .count();
+
+    assert_eq!(
+        must_use_count, 6,
+        "Expected exactly 6 #[must_use] attributes in preprocess.rs, but found {}. \
+         The scope of this issue is limited to 6 specific functions. \
+         If more #[must_use] attributes are needed, that should be a separate issue.",
+        must_use_count
+    );
+}
diff --git a/crates/diffguard-types/src/lib.rs b/crates/diffguard-types/src/lib.rs
index b634c06b..d9995763 100644
--- a/crates/diffguard-types/src/lib.rs
+++ b/crates/diffguard-types/src/lib.rs
@@ -133,7 +133,11 @@ pub struct DiffMeta {
     /// Stored as `u64` to avoid silent truncation for very large repositories
     /// (those with more than 2^32 - 1 unique files).
     pub files_scanned: u64,
-    pub lines_scanned: u32,
+    /// Number of distinct lines that were scanned.
+    ///
+    /// Stored as `u64` to avoid silent truncation for very large diffs
+    /// (those with more than 2^32 - 1 unique lines).
+    pub lines_scanned: u64,
 }
 
 /// A single rule match within a scoped file.
@@ -426,6 +430,29 @@ fn is_match_mode_any(mode: &MatchMode) -> bool {
     matches!(mode, MatchMode::Any)
 }
 
+// Utility for markdown escaping, used by rendering crates — kept here to avoid duplication across crates.
+pub fn escape_md(s: &str) -> String {
+    // Escapes special Markdown characters in table cell content.
+    //
+    // Escapes pipe (`|`), backtick (`` ` ``), hash (`#`), asterisk (`*`),
+    // underscore (`_`), open bracket (`[`), close bracket (`]`), and greater-than
+    // (`>`) characters by prefixing with backslash. Also escapes CRLF (`\r\n`)
+    // and LF (`\n`) line endings to prevent breaking the markdown table structure.
+    //
+    // These escapes are needed to prevent breaking the markdown table structure
+    // and prevent unintended markdown formatting.
+    s.replace('|', "\\|")
+        .replace('`', "\\`")
+        .replace('#', "\\#")
+        .replace('*', "\\*")
+        .replace('_', "\\_")
+        .replace('[', "\\[")
+        .replace(']', "\\]")
+        .replace('>', "\\>")
+        .replace('\r', "\\r")
+        .replace('\n', "\\n")
+}
+
 // ============================================================================
 // Per-directory override types
 // ============================================================================
diff --git a/crates/diffguard/src/main.rs b/crates/diffguard/src/main.rs
index c8cd2b8b..1c6aa358 100644
--- a/crates/diffguard/src/main.rs
+++ b/crates/diffguard/src/main.rs
@@ -29,7 +29,7 @@ use diffguard_types::{
     CHECK_SCHEMA_V1, CODE_TOOL_RUNTIME_ERROR, CapabilityStatus, CheckReceipt, ConfigFile, DiffMeta,
     DirectoryOverrideConfig, FailOn, Finding, MatchMode, REASON_MISSING_BASE, REASON_NO_DIFF_INPUT,
     REASON_TOOL_ERROR, RuleConfig, Scope, Severity, ToolMeta, Verdict, VerdictCounts,
-    VerdictStatus,
+    VerdictStatus, escape_md,
 };
 
 mod config_loader;
@@ -1689,20 +1689,6 @@ fn render_finding_row_with_baseline(f: &Finding, is_baseline: bool) -> String {
     )
 }
 
-/// Escapes special markdown characters in a string.
-fn escape_md(s: &str) -> String {
-    s.replace('|', "\\|")
-        .replace('`', "\\`")
-        .replace('#', "\\#")
-        .replace('*', "\\*")
-        .replace('_', "\\_")
-        .replace('[', "\\[")
-        .replace(']', "\\]")
-        .replace('>', "\\>")
-        .replace('\r', "\\r")
-        .replace('\n', "\\n")
-}
-
 /// Renders markdown output with baseline/new annotations.
 ///
 /// This modifies the table output to include baseline/new annotations for each finding.