feat(bridge): post a NEW comment per !testme (not edit-in-place)

Operator preference: each !testme should get its own comment response so a
re-run is visible in the PR timeline. process_testme now always posts a fresh
⏳ placeholder comment; watch_and_reflect edits THAT comment to the result.
(Was: reuse/edit a single marker comment in place — which made re-runs on an
unchanged head invisible, only updating commit status.)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

bridge/bridge.py

@@ -287,15 +287,11 @@ def process_testme(full_name, owner, name, number, user, comment_id, source, qui
     run_url = f"{DRONE_URL}/{CI_REPO}/{num}"
     post_commit_status(owner, name, head["sha"], "pending", run_url, "cc-ci run in progress")
     mode = " **(--quick: lower-confidence fast lane; does not gate merge)**" if quick else ""
-    # R2/U3: one comment per PR, updated in place. Reuse the existing marked comment if present
-    # (re-`!testme` refreshes it back to the ⏳ placeholder), else post a new one.
+    # One NEW comment PER `!testme` (operator preference 2026-06-02): post a fresh ⏳ placeholder each
+    # run so every re-`!testme` is visible in the PR timeline; watch_and_reflect then edits THIS
+    # comment to its result. (Previously a single marked comment was reused/edited in place.)
     start_body = start_comment_body(name, head["sha"], run_url, mode)
-    existing = find_existing_comment(full_name, number)
-    if existing:
-        edit_comment(owner, name, existing, start_body)
-        cid = existing
-    else:
-        cid = post_comment(owner, name, number, start_body)
+    cid = post_comment(owner, name, number, start_body)
     log(
         f"[{source}] triggered build {num} for {name}@{head['sha'][:8]} "
         f"(PR #{number}, comment {comment_id}) by {user}"