feat(06-07): scheduled() cron tick wired — factory, loadGraph street memo, crons trigger (GREEN)

- webhook.ts: createExportedHandler(opts) factory (offline send capture via
  baseFetch); scheduled() wraps runGuidanceCronTick in ctx.waitUntil —
  fail-closed unconfigured gate, paginated guidance: KV list (list_complete
  respected), loadGraph awaited ONCE per tick (the shared R2 memo), per-key
  getGuidanceSession → projectTurnCards → sendPhoto to envelope.chat_id ONLY
  (T-06-02), every log a [guidance-cron] category, zero KV writes
- guidance-sessions.ts: GUIDANCE_KEY_PREFIX exported — the ONE key-scheme
  authority (list scans derive prefix + slice ids from it)
- wrangler.jsonc: triggers.crons */1 * * * * (60 s scan, cadence in code)
- guidance-cron.test.mjs GREEN completion: GC-C3/C5/C8/C9 wire the recording
  baseFetch through the factory (the header-documented seam — they defined
  the recorder but never passed it); GC-C7 uses readdirSync (require is
  undefined in ESM); GC-C1/C8/C9 drain inside the withConsole window (the
  tick's logs fire under waitUntil)
- guidance-envelope.test.mjs: GE7 allows the GUIDANCE_KEY_PREFIX named import
- 125/125 bot tests green; bot:typecheck clean

bot/test/guidance-envelope.test.mjs

@@ -193,6 +193,7 @@ test("GE7 consumer shape — every bot/src import of guidance-sessions is a NAME
     "GUIDANCE_SESSION_TTL_SECONDS",
     "GuidanceSessionEnvelope",
     "GuidanceRouteSnapshot",
+    "GUIDANCE_KEY_PREFIX",
   ]);
   const NAMED_RE = /\bimport\s+(?:type\s+)?\{([^}]*)\}\s*from\s*["'][^"']*guidance-sessions[^"']*["']/g;
   for (const file of tsFilesUnder(srcDir)) {