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/ai_review.py

@@ -5,8 +5,9 @@ Runs as a Gitea Actions step OR is called by the central webhook server
 (`webhook_server.py`). Fetches a PR diff, asks glm-5.2:cloud (via the on-network
 headroom proxy, Anthropic /v1/messages format) to review it, and posts the
 findings back as `pragent-bot` — as a **review summary** plus **inline line
-comments** with apply-able ```suggestion blocks where the model could produce
-them and the line anchors cleanly to the post-change file.
+comments** with a fenced suggested-fix block (tagged with the file's language so
+Gitea syntax-highlights it) where the model could produce one and the line
+anchors cleanly to the post-change file.
 
 Features (pilot v2):
   - **Dedupe / persistence:** Gitea itself is the source of truth. Before
@@ -22,9 +23,12 @@ Features (pilot v2):
     findings with `path`/`line`. We parse the diff hunks to learn which
     `(path, new_line)` pairs are valid post-change anchors and post each
     anchored finding as a positional review comment; the `suggestion` field, if
-    non-empty, is wrapped in a ```suggestion fence so Gitea renders an
-    apply-button. Findings that don't anchor (bad line, unchanged file, etc.)
-    are folded into the summary body as plain bullets.
+    non-empty, is wrapped in a fenced code block tagged with the file's language
+    (via `_lang_for_path`) so Gitea syntax-highlights it. Gitea 1.26.x has no
+    GitHub-style "Apply suggestion" button, so a language-tagged block is used
+    for highlighting instead of a ```suggestion fence. Findings that don't
+    anchor (bad line, unchanged file, etc.) are folded into the summary body as
+    plain bullets.
 
 Fail-open by design: any error becomes a short "review failed" review comment,
 and review_pr never raises. Stdlib only — no pip install.
@@ -431,19 +435,51 @@ def split_findings(findings: list[dict], anchors: dict[str, set[int]]) -> tuple[
     return anchored, unanchored
 
 
+def _lang_for_path(path: str) -> str:
+    """Map a file extension to a chroma language tag for fenced code blocks.
+
+    Used so the suggested-fix block is syntax-highlighted in Gitea. Gitea 1.26.x
+    has no GitHub-style "Apply suggestion" button (the ```suggestion fence is
+    just an unknown-language code block → plain monospace, no apply), so we tag
+    the block with the file's real language for highlighting instead.
+    """
+    ext = path.rsplit(".", 1)[-1].lower() if "." in path else ""
+    return {
+        "java": "java", "kt": "kotlin", "scala": "scala", "groovy": "groovy",
+        "ts": "typescript", "tsx": "tsx", "js": "javascript", "jsx": "jsx",
+        "mjs": "javascript", "cjs": "javascript",
+        "py": "python", "pyi": "python",
+        "go": "go", "rs": "rust", "rb": "ruby", "php": "php",
+        "c": "c", "h": "c", "cpp": "cpp", "cc": "cpp", "hpp": "cpp",
+        "cs": "csharp", "swift": "swift", "m": "objc",
+        "sh": "bash", "bash": "bash", "zsh": "bash",
+        "yml": "yaml", "yaml": "yaml", "json": "json", "jsonc": "json",
+        "toml": "toml", "ini": "ini", "cfg": "ini",
+        "html": "html", "htm": "html", "css": "css", "scss": "scss",
+        "xml": "xml", "svg": "xml", "sql": "sql",
+        "md": "markdown", "dockerfile": "dockerfile",
+    }.get(ext, "")
+
+
 def inline_comment_body(f: dict) -> str:
     """Render one finding as a positional review-comment body.
 
-    Includes a ```suggestion fence only if the model produced non-empty
-    replacement code. Gitea renders that as an apply-able suggestion. Appends a
-    `📎 ref:` link when the finding carries a `reference` URL.
+    Includes a fenced suggested-fix block only if the model produced non-empty
+    replacement code. The fence is tagged with the file's language (via
+    `_lang_for_path`) so Gitea syntax-highlights it — Gitea 1.26.x has no
+    GitHub-style "Apply suggestion" button (```suggestion is just an
+    unknown-language block there → plain monospace), so a language-tagged block
+    is strictly more readable and loses nothing. Appends a `📎 ref:` link when
+    the finding carries a `reference` URL.
     """
     sev = f["severity"].upper()
     body = f"**[{sev}]** {f['problem']}"
     if f["fix"]:
         body += f"\n\nFix: {f['fix']}"
     if f["suggestion"]:
-        body += f"\n\n```suggestion\n{f['suggestion']}\n```"
+        lang = _lang_for_path(f.get("path", ""))
+        fence = f"```{lang}" if lang else "```"
+        body += f"\n\n{fence}\n{f['suggestion']}\n```"
     ref = f.get("reference", "")
     if ref:
         body += f"\n\n📎 ref: {ref}"
@@ -632,8 +668,8 @@ def post_inline_review(
     honored here and silently leave the comment unpositioned (Gitea then renders
     a file-level comment on EVERY diff line of the file, which is the flood we
     hit). `f["line"]` is already a validated post-change (RIGHT-side) line from
-    `split_findings`, so it maps directly to `new_position`. The body carries the
-    ```suggestion fence when the model produced replacement code.
+    `split_findings`, so it maps directly to `new_position`. The body carries a
+    language-tagged fenced code block when the model produced replacement code.
     """
     comments = [
         {