Split tokens (#1)

The agent and the bot are now two accounts, and the runner is one Deno script.

- `author-token` (was `gitea-token`): commits, pushes, and opens pull requests; the agent sees it as `GITEA_TOKEN`, and commits use that account's login and email.
- `reviewer-token`: posts comments and reviews as the bot; withheld from the agent's environment so it can never approve as the bot.
- A `pull_request` run posts a review instead of a comment: `REQUEST_CHANGES` when the response mentions `@bot`, `COMMENT` when the run failed, `APPROVED` otherwise. Gitea refuses self-approval, so the two accounts must differ.
- The reviewer checks the whole repository against `commons/code-rules`, which is fetched and embedded in the prompt, and requests changes for violations even when the diff did not cause them.
- `run.ts` replaces the three shell scripts plus `jq`, `envsubst`, and `ansifilter`; only `deno` is added to the install step, per the rules' Deno-over-Node policy. A `.gitea` workflow runs `deno fmt`, `lint`, and `check`.

Callers must rename `gitea-token` and add `reviewer-token` (`write:issue` and `write:repository` scopes). A rejection stays until the bot reviews again, so callers that want it lifted after a fix should trigger on `pull_request: [opened, synchronize]`.

Verified with a fake `claude` binary against this PR in an isolated `HOME`: git author configured from the token, prompt rendered with rules and comment history, events streamed, reviewer token absent from the agent's environment, review posted (then deleted).

Reviewed-on: #1
Co-authored-by: Danny Kim <temeddix@gmail.com>
Co-committed-by: Danny Kim <temeddix@gmail.com>

.gitea/workflows/check.yml

@@ -0,0 +1,17 @@
+name: Check
+
+on:
+  pull_request:
+    branches: [main]
+
+jobs:
+  deno:
+    runs-on: self-hosted
+    steps:
+      - uses: actions/checkout@v4
+
+      - run: apt-get update && apt-get install -y unzip
+
+      - uses: denoland/setup-deno@v2
+
+      - run: deno fmt --check . && deno lint . && deno check run.ts