feat(search): overhaul search output formatting (GIT-5)

Phase 1: Add source_entity_iid to search results via CASE subquery on
hydrate_results() for all 4 source types (issue, MR, discussion, note).
Phase 2: Fix visual alignment - compute indent from prefix visible width.
Phase 3: Show compact relative time on title line.
Phase 4: Add drill-down hint footer (lore issues <iid>).
Phase 5: Move labels to --explain mode, limit snippets to 2 terminal lines.
Phase 6: Use section_divider() for results header.

Also: promote strip_ansi/visible_width to public render utils, update
robot mode --fields minimal search preset with source_entity_iid.

src/cli/render.rs

@@ -569,6 +569,32 @@ pub fn terminal_width() -> usize {
     80
 }
 
+/// Strip ANSI escape codes (SGR sequences) from a string.
+pub fn strip_ansi(s: &str) -> String {
+    let mut out = String::with_capacity(s.len());
+    let mut chars = s.chars();
+    while let Some(c) = chars.next() {
+        if c == '\x1b' {
+            // Consume `[`, then digits/semicolons, then the final letter
+            if chars.next() == Some('[') {
+                for c in chars.by_ref() {
+                    if c.is_ascii_alphabetic() {
+                        break;
+                    }
+                }
+            }
+        } else {
+            out.push(c);
+        }
+    }
+    out
+}
+
+/// Compute the visible width of a string that may contain ANSI escape sequences.
+pub fn visible_width(s: &str) -> usize {
+    strip_ansi(s).chars().count()
+}
+
 /// Truncate a string to `max` characters, appending "..." if truncated.
 pub fn truncate(s: &str, max: usize) -> String {
     if max < 4 {
@@ -1459,24 +1485,19 @@ mod tests {
 
     // ── helpers ──
 
-    /// Strip ANSI escape codes (SGR sequences) for content assertions.
+    /// Delegate to the public `strip_ansi` for test assertions.
     fn strip_ansi(s: &str) -> String {
-        let mut out = String::with_capacity(s.len());
-        let mut chars = s.chars();
-        while let Some(c) = chars.next() {
-            if c == '\x1b' {
-                // Consume `[`, then digits/semicolons, then the final letter
-                if chars.next() == Some('[') {
-                    for c in chars.by_ref() {
-                        if c.is_ascii_alphabetic() {
-                            break;
-                        }
-                    }
-                }
-            } else {
-                out.push(c);
-            }
-        }
-        out
+        super::strip_ansi(s)
+    }
+
+    #[test]
+    fn visible_width_strips_ansi() {
+        let styled = "\x1b[1mhello\x1b[0m".to_string();
+        assert_eq!(super::visible_width(&styled), 5);
+    }
+
+    #[test]
+    fn visible_width_plain_string() {
+        assert_eq!(super::visible_width("hello"), 5);
     }
 }