fix(review): language-tagged suggestion fence for Gitea syntax highlighting

Gitea 1.26.x has no GitHub-style 'Apply suggestion' button — a ```suggestion
fence is just an unknown-language code block, so chroma does not highlight it
and there is no apply control. Switch inline_comment_body to wrap the suggested
fix in a fence tagged with the file's language (new _lang_for_path helper,
.java→java, .ts→typescript, .py→python, ...), so Gitea syntax-highlights the
code. No capability lost (there was never an apply button on this Gitea
version). Correct the docstrings/skills/README that wrongly claimed an
apply-button was rendered.

Co-Authored-By: Claude <noreply@anthropic.com>

.opencode/skills/findings-schema/SKILL.md

@@ -42,8 +42,10 @@ message — so the JSON must be the last thing, and it must be valid.
 - `suggestion` — the literal new code replacing the flagged line(s). Minimal,
   just the changed lines, indented as they appear in the file. **Empty string**
   when no safe textual replacement exists (missing test, architectural note, a
-  fix that needs context beyond one hunk). This is wrapped in a ```suggestion
-  fence → Gitea renders an **apply button**.
+  fix that needs context beyond one hunk). The pilot wraps this in a fenced code
+  block tagged with the file's language so Gitea syntax-highlights it. (Gitea
+  1.26.x has no GitHub-style "Apply suggestion" button, so a ```suggestion fence
+  is not used — a language-tagged fence gives highlighting and loses nothing.)
 - `reference` — a URL (CVE, library docs, spec) backing the finding, or `""`.
   Only link authoritative sources; don't fabricate URLs.