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>

tests/pilot/test_ai_review.py

@@ -268,14 +268,23 @@ def test_inline_comment_body_with_suggestion():
     body = inline_comment_body(f)
     assert "**[HIGH]**" in body
     assert "bad" in body
-    assert "```suggestion\n" in body
+    # no extension → bare fence (Gitea 1.26.x has no apply-suggestion; we tag
+    # with the file language for highlighting instead of ```suggestion)
+    assert "```\ngood()\n```" in body
     assert "good()" in body
 
 
+def test_inline_comment_body_suggestion_lang_tagged():
+    f = {"severity": "high", "path": "src/Foo.java", "line": 1,
+         "problem": "bad", "fix": "swap", "suggestion": "good();"}
+    body = inline_comment_body(f)
+    assert "```java\ngood();\n```" in body
+
+
 def test_inline_comment_body_no_suggestion():
     f = {"severity": "low", "path": "a", "line": 1, "problem": "p", "fix": "f", "suggestion": ""}
     body = inline_comment_body(f)
-    assert "```suggestion" not in body
+    assert "```" not in body
     assert "Fix: f" in body