fix(revive): double --resume flag when revive + session_persist are both active

[CoreyRDean]

Follow-up from Codex review on PR #56 (P2, lib/run-job.sh:469).

Problem

Revive injects `--resume <session_id>` from the revive override file (line ~188 after commit a408508). The existing session-persistence block later appends another `--resume` when the job has `session_persist: true` and a `.session-id` file exists.

Result: the `claude` command gets two `--resume` flags on revive runs for session-persistent jobs. Behavior is undefined — last-flag-wins would pick the stale persisted session, losing the explicit tombstone session the user is trying to revive.

Fix

The revive override takes precedence. When `REVIVE_SESSION_ID` is set, skip the session_persist `--resume` append entirely. A guard like:

```sh
if [ -z "$REVIVE_SESSION_ID" ] && [ -n "$SESSION_PERSIST" ] && [ -f "$SESSION_ID_FILE" ]; then
CLAUDE_ARGS=("--resume" "$(cat $SESSION_ID_FILE)" "${CLAUDE_ARGS[@]}")
fi
```

(Adjust to match actual variable names in the file.)

Acceptance

• Revive of a `session_persist: true` job produces exactly one `--resume` flag in the `claude` invocation.
• Revived session matches the tombstone's session_id, not the persisted session file.
• Test covering: (a) revive of session_persist job, (b) revive of non-session_persist job, (c) normal run of session_persist job (no revive).