chore(stamphog): Raise auto-review line ceiling to 1000

[charlesvien]

Problem

Stamphog hard-refuses any PR over 500 changed lines, and team-code PRs keep landing just over that. Per Julian, this repo owns its copy of the agent so the limit is ours to tune. Upstream's .stamphog/policy.yml config doesn't apply here yet: our copy predates it and hardcodes the gate.

Changes

Raise MAX_LINES from 500 to 1000 in tools/pr-approval-agent/gates.py and update the README. MAX_FILES stays at 20. The refusal message in review_pr.py interpolates the constant, so no other references exist.

How did you test this?

No tests run. Grepped the tool and workflow for every reference to the ceiling; the constant and one README line are the only two.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

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[greptile-apps]

_{Reviews (1): Last reviewed commit: "raise stamphog line ceiling to 1000" | Re-trigger Greptile}

[github-actions]

Trivial config change raising the auto-review line ceiling in tooling only — no production code affected.