fix(config_help): slice file from start_line instead of using --pattern

--section-header pins section-delimiter lines as sticky headers, which
removes them from ov's pattern search scope. --pattern "# 3. KEY BINDINGS"
therefore reports "not found" even though the line exists.

Replace --pattern with tail -n +$start_line piped before ov. The file
naturally starts at the target section so no search is needed, section
nav (Space/^) still works for all subsequent sections, and the sidebar
is populated correctly via --section-delimiter "^#".

functions/config_help.fish

@@ -10,6 +10,9 @@
 #   If a section keyword is provided, the pager opens at the first heading
 #   that matches the keyword. Lookup order: docs/fish-config.index (exact
 #   keyword aliases), then a normalized heading scan as fallback.
+#   When jumping to a section the file is sliced from that line onwards so
+#   ov never has to search through section-header lines (which --section-header
+#   pins and hides from pattern matching).
 #
 # ARGUMENTS
 #   section  Optional keyword to jump to a matching section heading
@@ -35,15 +38,15 @@ function config_help --description 'Open the offline fish shell configuration ma
         return 1
     end
 
-    # ── Resolve section ──────────────────────────────────────────
+    # ── Resolve section start line ───────────────────────────────
     # 1. Look up keyword in fish-config.index (keyword → exact heading text).
     # 2. Fall back to normalized scan of heading lines if not in index.
     # 3. Resolve start_line via grep -F on the heading text (immune to line
     #    number drift — only breaks if the heading itself is renamed).
     set -l start_line 1
-    set -l found_text ""
     if test -n "$argv[1]"
         set -l norm_kw (string lower -- $argv[1] | string replace -ra '[^a-z0-9]' '')
+        set -l found_text ""
 
         # ── Index lookup ─────────────────────────────────────────
         if test -f "$idx_file"
@@ -85,28 +88,34 @@ function config_help --description 'Open the offline fish shell configuration ma
     end
 
     # ── Viewer fallback chain ────────────────────────────────────
-    # ov matches section-delimiter against logical (displayed) text, so "^#"
-    # works on bat-colored output — no ANSI regex needed.
+    # When jumping to a section, slice the file from start_line so ov
+    # opens with that section at the top without needing --pattern.
+    # --pattern on section-delimiter lines is unreliable: --section-header
+    # pins those lines as sticky headers, removing them from search scope.
     # Section nav: Space (next), ^ (previous), Alt+u (section list sidebar).
-    # --pattern uses the exact heading text for a precise one-line match.
     if type -q ov; and type -q bat
         set -l ov_args \
             --section-delimiter "^#" \
             --section-header
-        if test -n "$found_text"
-            set -a ov_args --pattern (string escape --style=regex -- $found_text)
+        if test $start_line -gt 1
+            bat --color=always --style=plain --language=markdown "$doc_file" \
+                | tail -n +$start_line \
+                | ov $ov_args
+        else
+            bat --color=always --style=plain --language=markdown "$doc_file" \
+                | ov $ov_args
         end
-        ov $ov_args (bat --color=always --style=plain --language=markdown "$doc_file" | psub)
 
     # ov alone: section navigation on raw Markdown; no code highlighting.
     else if type -q ov
         set -l ov_args \
             --section-delimiter "^#" \
             --section-header
-        if test -n "$found_text"
-            set -a ov_args --pattern (string escape --style=regex -- $found_text)
+        if test $start_line -gt 1
+            tail -n +$start_line "$doc_file" | ov $ov_args
+        else
+            ov $ov_args "$doc_file"
         end
-        ov $ov_args "$doc_file"
 
     # bat alone: syntax highlighting with built-in paging; no line jump.
     else if type -q bat