chore(v0.3.0): rename fast-LLM env vars to TIMEWEB_* (match other projects)

Aligns with the user's other repos (proso) which use TIMEWEB_API_GROK /
TIMEWEB_URL_GROK. Single naming convention across projects avoids the
'which env var was it for this repo' mental tax.

  PEPA_FAST_LLM_BASE_URL → TIMEWEB_BASE_URL
  PEPA_FAST_LLM_API_KEY  → TIMEWEB_API_KEY
  PEPA_FAST_LLM_MODEL    → TIMEWEB_MODEL
  PEPA_FAST_LLM_TIMEOUT_MS → TIMEWEB_TIMEOUT_MS

Provider still works with any OpenAI-compatible endpoint — TimeWeb is
the default but the variable name doesn't lock us in. Tests + docs +
.env / .env.example updated.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

dev/v0.3.0/PLAN.md

@@ -65,7 +65,7 @@ L10 village_full   глобальная цель (ферма + дом + сосе
 - `runtime/coach/advice.js`: `normalisePreferSkill` строго отбрасывает
   всё, что не в реестре (raise log, не дрейфит на fuzzy)
 - `runtime/llm/provider.js` — OpenAI-совместимый клиент, конфигурируется
-  через env (`PEPA_FAST_LLM_BASE_URL`, `_API_KEY`, `_MODEL`); graceful
+  через env (`TIMEWEB_BASE_URL`, `TIMEWEB_API_KEY`, `TIMEWEB_MODEL`); graceful
   fallback "no-op" если env не задан (бот не падает)
 - `runtime/coach/fast-advisor.js` — функция `advise({snapshot, reason})`
   с rate-limit (макс. 6 вызовов/час), таймаут 8с, JSON-парсинг ответа

dev/v0.3.0/STATUS.md

@@ -22,10 +22,10 @@ fixed: (a) Pi now sees the real registry in its system prompt,
     namespace, with "USE ONLY THESE, never invent" instruction
 - [`runtime/llm/provider.js`](../../runtime/llm/provider.js) —
   OpenAI-compatible chat client, env-driven:
-  - `PEPA_FAST_LLM_BASE_URL` (default `https://api.openai.com/v1`)
-  - `PEPA_FAST_LLM_API_KEY` (required to enable; safe no-op otherwise)
-  - `PEPA_FAST_LLM_MODEL` (required)
-  - `PEPA_FAST_LLM_TIMEOUT_MS` (default 8000)
+  - `TIMEWEB_BASE_URL` (default `https://api.openai.com/v1`)
+  - `TIMEWEB_API_KEY` (required to enable; safe no-op otherwise)
+  - `TIMEWEB_MODEL` (required)
+  - `TIMEWEB_TIMEOUT_MS` (default 8000)
   - Supports JSON-mode via `response_format: { type: "json_object" }`
   - Surfaces `not_configured`, `no_model`, `http_<status>`,
     `network_error`, `timeout`, `bad_json` codes
@@ -167,9 +167,9 @@ Tests: 332 green (was 315 on rc.2, +17 new):
    start growing as the registry feedback closes the loop.
 3. **Set fast-advisor env when ready to test**:
    ```bash
-   export PEPA_FAST_LLM_BASE_URL="https://<timeweb-endpoint>/v1"
-   export PEPA_FAST_LLM_API_KEY="<key>"
-   export PEPA_FAST_LLM_MODEL="gpt-5-mini"
+   export TIMEWEB_BASE_URL="https://<timeweb-endpoint>/v1"
+   export TIMEWEB_API_KEY="<key>"
+   export TIMEWEB_MODEL="gpt-5-mini"
    ```
    The advisor still isn't auto-triggered in rc.1 — it's wired in rc.3.
 4. **Pick the next rc** from PLAN.md.