fix(pr): pin agent-meta marker, add harness field

skills/land/SKILL.md

@@ -92,7 +92,12 @@ Then **end the turn**. Do not wait for anything.
 Each reason is one query. Nothing new: return silently, per
 `COMMON.md`. Update the state file whenever the phase or head SHA
 changes. Every body you post ends with the metadata marker from
-`COMMON.md`.
+`COMMON.md`, verbatim — the `agent-meta` JSON object, never an
+invented tag:
+
+```
+<!-- agent-meta: {"model":"<model-id>","harness":"<harness>","session":"<sid>"} -->
+```
 
 ### `reason=comments`
 

skills/pr-common/COMMON.md

@@ -8,9 +8,9 @@ when there is work, the skill decides what to do about it.
 
 `bin/reviewer-poll.ts` runs as a systemd user service and is the only
 thing polling a forge. It reads metadata — `updated_at`, `state`,
-`draft`, `mergeable`, head SHA — and touches comment bodies in exactly
+`draft`, `mergeable`, head SHA. It never reads comment bodies, so the
-one case: checking the metadata marker (below) to decide whether new
+metadata marker (below) is for local tooling only. When a PR looks
-comments are the target session's own. When a PR looks changed it
+changed it
 either creates a session for it or sends a one-line hint to the session
 that already owns it.
 
@@ -92,10 +92,16 @@ issue comment, reply — ends with a hidden marker as its last line,
 after a blank line:
 
 ```
-<!-- agent-meta: {"model":"<model-id>","session":"<sid>"} -->
+<!-- agent-meta: {"model":"<model-id>","harness":"<harness>","session":"<sid>"} -->
 ```
 
+Post that marker verbatim — a JSON object with those keys. Do not
+invent a different marker, and do not replace it with a bare tag like
+`<!-- pr-daemon:land -->`; local tooling parses the JSON.
+
 - `model`: the model id you are running as (e.g. `claude-fable-5`)
+- `harness`: the agent harness you run in — `claude-code`, `codex`,
+  `pi`, `opencode`
 - `session`: first 8 chars of your harness's session id —
   `$CLAUDE_CODE_SESSION_ID`, `$PI_SESSION_ID`, or whatever your harness
   sets; omit only if none exists

skills/review-pr/SKILL.md

@@ -122,6 +122,11 @@ this section exists to prevent.
 
 End the review body and every `comments[]` body with the metadata
 marker from `COMMON.md` (skip a review body that is otherwise empty).
+Post it verbatim — the `agent-meta` JSON object, never an invented tag:
+
+```
+<!-- agent-meta: {"model":"<model-id>","harness":"<harness>","session":"<sid>"} -->
+```
 
 Only after the user's go-ahead on an unlisted repo. Record every id you post
 in the same step, or the next hint reads your own review as new