chore: repo cleanups + start OpenCode in ~/dev - #1

- opencode-webhooks README: replace stale `x-email-from` header reference with JSON `from` field (finding #1).
- http.ts: rewrite MAX_BODY_BYTES comment (no longer about RFC822); add MAX_EMAIL_BODY_BYTES = 64 KB and an optional maxBytes arg to readBodyBytes; email handler now uses the tighter cap (finding #2).
- cloudflare-email-worker README: note that a malformed regex literal in ALLOWED_SENDERS will throw at module init and the worker won't start (finding #3).
- email handler: parseEmailEvent's `str` now throws on non-string for required fields (from/to/subject/message_id) so the 400 detail names the offending field instead of misleading 'missing' messages (finding #4).
- Test gap for email identity fallback chain tracked in #14; no tests added in this commit (finding #5).

… SIDECAR_URL → WEBHOOK_URL (#13)

* refactor(email-worker): wrangler.json, inline ALLOWED_SENDERS, rename SIDECAR_URL → WEBHOOK_URL

- Replace wrangler.toml with wrangler.json (with $schema reference for
  editor validation). TOML and JSON are both first-class wrangler
  config formats; JSON keeps the worker package consistent with the
  rest of the repo's config files (package.json, tsconfig.json,
  webhooks.json).
- Move ALLOWED_SENDERS out of wrangler vars and into a top-level
  TypeScript const at the head of src/index.ts. The allowlist is
  PR-reviewed code now (typed as readonly string[]), compiled once at
  module load (zero per-request parse overhead), and a malformed regex
  fails the deploy instead of silently dropping at runtime. The Env
  shape no longer needs an ALLOWED_SENDERS field.
- Rename SIDECAR_URL → WEBHOOK_URL in wrangler.json vars, the Env
  interface, and the fetch call. 'Sidecar' was misleading anyway —
  the plugin is in-process with opencode, not a sidecar process.
  WEBHOOK_URL clearly names what it points at: the plugin's
  /webhooks/email endpoint.

* feat(email): worker becomes dumb pipe — unconditional forward + JSON event

The Cloudflare Email Worker now does two things per inbound email:

  1. message.forward(env.FORWARD_TO) unconditionally (if set), so every
     email reaches the operator's real inbox preserving DKIM. Wrapped
     in try/catch so a misconfigured FORWARD_TO doesn't block webhook
     dispatch — failure is logged loudly and we continue.
  2. If the From address is in ALLOWED_SENDERS, build a small JSON
     event from the headers we route on (from, to, subject,
     message_id, in_reply_to, references, list_id, x_github_reason,
     x_github_sender), HMAC-sign it, and POST as application/json to
     WEBHOOK_URL.

The worker no longer parses RFC822 in the plugin path — it just hands
Cloudflare's already-parsed headers to the plugin verbatim. The body
is never sent at all (it never was used; canonical state comes from
the GitHub API).

Plugin side:
- handlers/email.ts: reads req.json() instead of parsing RFC822;
  validates the event shape; everything downstream (identity, synth,
  dispatch) is unchanged.
- email/identity.ts: accepts the EmailEvent JSON shape instead of an
  EmailHeaders object. Same regex matchers; same in-reply-to /
  references fallback chain.
- email/synthesize.ts: reads metadata directly from the event object.
- email/parse.ts: deleted (no more RFC822 parsing).

Other changes:
- wrangler.json: added FORWARD_TO var (optional) and
  observability.logs.enabled = true so 'wrangler tail' and the
  Cloudflare dashboard show structured logs.
- READMEs: updated wire format, architecture diagrams, failure-mode
  table on the worker side.

Verified: bun run typecheck passes for both packages; wrangler deploy
--dry-run accepts the new config with both vars bound.

* fix: review findings on PR #13 (dumb-pipe + wrangler.json)

- opencode-webhooks README: replace stale `x-email-from` header reference with JSON `from` field (finding #1).
- http.ts: rewrite MAX_BODY_BYTES comment (no longer about RFC822); add MAX_EMAIL_BODY_BYTES = 64 KB and an optional maxBytes arg to readBodyBytes; email handler now uses the tighter cap (finding #2).
- cloudflare-email-worker README: note that a malformed regex literal in ALLOWED_SENDERS will throw at module init and the worker won't start (finding #3).
- email handler: parseEmailEvent's `str` now throws on non-string for required fields (from/to/subject/message_id) so the 400 detail names the offending field instead of misleading 'missing' messages (finding #4).
- Test gap for email identity fallback chain tracked in #14; no tests added in this commit (finding #5).

The webhook gate dispatched events whose sender is the bot itself (e.g.
jared's own PR review submission on a jared-labeled PR). That woke a
container and booted Flue only for the in-container router to discard it
via skip condition #1 (sender == $ME) — a wasted dispatch per self action.

Mirror that skip at the Worker gate: drop events where sender == botLogin,
except check_suite / workflow_run (CI on the bot's own commits is
actionable and feeds fix-ci / mark-pr-ready), matching the router exception.

Co-authored-by: Cursor <cursoragent@cursor.com>