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>

pilot/README-webhook.md

@@ -37,13 +37,14 @@ ai_review.review_pr()  (same core the CI-step uses)
    7. post review       → POST .../pulls/{i}/reviews  (event: COMMENT) as pragent-bot
       - prose summary → review body intro
       - anchored findings → inline line comments, body wraps `suggestion` in a
-        ```suggestion fence (Gitea renders an apply-button); reference → 📎 ref link
+        language-tagged fenced code block (Gitea syntax-highlights it; Gitea
+        1.26.x has no apply-suggestion button); reference → 📎 ref link
       - unanchored findings → summary-body bullets
       - summary body carries the <!-- pragent:sha=... --> marker for dedupe
 ```
 
-Fail-open. No duplicate per commit (dedupe). Inline comments + apply-able
-suggestions where the line anchors cleanly. Repo-local focus via
+Fail-open. No duplicate per commit (dedupe). Inline comments + syntax-highlighted
+suggested-fix blocks where the line anchors cleanly. Repo-local focus via
 `.pr-review.json`. Prior reviews fed as context so re-pushes synthesize instead
 of repeating (light version of framework §6.1).