feat(review): mark-reviewed action + §7 catalog unreviewed filter (§22.4c)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/bot.py

@@ -1069,6 +1069,56 @@ class Bot:
         )
         return pr
 
+    # ----- §22.4c: mark-reviewed (direct main write) -----
+
+    async def mark_entry_reviewed(
+        self,
+        actor: Actor,
+        *,
+        org: str,
+        meta_repo: str,
+        slug: str,
+        reviewed_by: str,
+        reviewed_at: str,
+    ) -> None:
+        """Clear §22.4c unreviewed on an active entry by rewriting its
+        frontmatter on main. Stamps the commit with the §6.5 On-behalf-of
+        trailer and writes an actions-log row, mirroring the graduation
+        stamp's bot-write shape."""
+        from . import entry as entry_mod
+
+        path = f"rfcs/{slug}.md"
+        result = await self._gitea.read_file(org, meta_repo, path, ref="main")
+        if result is None:
+            raise GiteaError(404, f"{path} not found")
+        text, sha = result
+        e = entry_mod.parse(text)
+        e.unreviewed = False
+        e.reviewed_at = reviewed_at
+        e.reviewed_by = reviewed_by
+        commit_message = _stamp_single(f"Mark {slug} reviewed", actor)
+        result2 = await self._gitea.update_file(
+            org, meta_repo, path,
+            content=entry_mod.serialize(e),
+            sha=sha,
+            message=commit_message,
+            branch="main",
+            author_name=actor.display_name,
+            author_email=actor.email or f"{actor.gitea_login}@users.noreply",
+        )
+        commit_sha = (
+            result2.get("commit", {}).get("sha")
+            or result2.get("content", {}).get("sha")
+            or ""
+        )
+        _log(
+            actor,
+            "mark_reviewed",
+            rfc_slug=slug,
+            bot_commit_sha=commit_sha,
+            details={"reviewed_by": reviewed_by, "reviewed_at": reviewed_at},
+        )
+
     # ----- Per-RFC repo: seeding (test/dev fixtures, future graduation) -----
 
     async def ensure_rfc_repo_seed(