Add Gmail+Email Worker hybrid mail path and private runtime config

Prefer Cloudflare Worker KV for verification codes with optional short IMAP
fallback disabled for private deploy; track config.json/.env for private repo.
Also add worker project, protocol mint backoff, and fail-fast Turnstile/mail
timeouts from batch runs.

.gitignore

@@ -6,10 +6,10 @@ __pycache__/
 dist/
 
 # secrets / local runtime
-config.json
+# config.json  # private repo: tracked intentionally
 config.local.json
 config.json.bak*
-.env
+# .env  # private repo: tracked intentionally
 accounts_*.txt
 emails_used.txt
 emails_error.txt
@@ -21,3 +21,6 @@ logs/
 *.log
 *.bak
 *.pid
+
+# local IDE
+.zcode/