Add config.json.example template; gitignore config.json

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VPNF37MP9Kuv62B1VBrZ1b

docs/superpowers/specs/2026-07-21-centralized-config-design.md

@@ -18,7 +18,7 @@ test-enforced (see Testing).
 ## Scoping decisions (user-confirmed 2026-07-21)
 
 1. **Secrets live in config.json** (gitignored). A committed
-   `config.example.json` carries placeholders. Env vars still override.
+   `config.json.example` carries placeholders. Env vars still override.
    The hardcoded credential fallbacks in `config.py` and `telegram_bot.py`
    are **deleted** — on a machine with neither config.json nor env vars, the
    bot refuses to start with an explicit error instead of silently using
@@ -39,7 +39,7 @@ test-enforced (see Testing).
 
 ## File schema
 
-`config.json` (gitignored; `config.example.json` committed with placeholders
+`config.json` (gitignored; `config.json.example` committed with placeholders
 for secrets and today's tuned values for everything else):
 
 ```json
@@ -128,7 +128,7 @@ block + one adapter class registered here. No shared base class extracted now
 - Create the local `config.json` populated with the **current live values**
   (the ones being deleted from source) so the running bot keeps working
   unchanged. `.gitignore` gains `config.json`.
-- Commit `config.example.json` with placeholders.
+- Commit `config.json.example` with placeholders.
 - CLAUDE.md: update the env-var table, repository map, and config section.
 - Post-merge recommendation (user action): rotate the Telegram token and
   Twelve Data key, since both are in git history.