feat(staging): deterministic staging-runner replacing LLM deployer on deploy-staging (ORCH-115)

Replace the LLM `deployer` agent on the `deploy-staging` stage (self-hosting
orchestrator) with a deterministic staging-runner intercepted in launch_job
BEFORE _spawn (the deploy-finalizer / post-deploy-monitor reserved-agent
precedent). The runner executes the SAME staging suite, maps the exit-code to
`staging_status:` via the existing self_deploy.map_exit_code_to_status contract,
writes 15-staging-log.md, and initiates the UNCHANGED check_staging_status gate
exactly as a finished LLM-deployer would.

Invariant (NFR-1): this replaces only the *producer* of the artifact — the
artifact contract, the gate / _parse_staging_status / check_staging_status name,
STAGE_TRANSITIONS, the machine-verdict key `staging_status:` and the DB schema are
byte-for-byte unchanged. Additive, under a kill-switch + repo-scope CSV,
never-raise, fail-safe back to the LLM path.

Two-level outcome (D5, anti ORCH-110): suite executed -> verdict -> advance
(FAILED -> the existing deploy-staging -> development rollback + developer-retry,
same as a FAILED LLM verdict); tool-error (suite did not execute) -> bounded DEFER
-> fail-closed FAILED + alert on exhaustion (infra != code fault; never a silent
advance / false green).

First implemented slice of the LLM determinization roadmap (ORCH-118 A6,
replace-deterministic-now).

- New leaf src/staging_runner.py (never-raise; proc_group tree-kill + timeout)
- launch_job intercept + _run_staging_runner_job (mirror _run_deploy_finalizer_job)
- config: ORCH_STAGING_RUNNER_* keys (enabled/repos/timeout/infra-retry budget)
- GET /queue staging_runner observability block
- docs: llm-call-sites/roadmap/usage-policy (A6 implemented; machine blocks +
  single-transport invariant intact), deployer.md (LLM branch -> fallback),
  CLAUDE.md, CHANGELOG.md, overview (tech-pipeline/tech-agents/tech-quality-security),
  .env.example
- tests/test_orch115_staging_runner.py (TC-01..TC-13); LLM anti-drift green (TC-14)

Refs: ORCH-115

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/overview/tech-agents.md

@@ -48,6 +48,12 @@ Machine-verdict ключи читаются гейтами **только из Y
 Особенность: промпт `deployer` сознательно на английском (самый safety-critical — несёт
 запреты self-hosting в видной рамке); остальные пять — на русском.
 
+Особенность (ORCH-115): на стадии `deploy-staging` для self-hosting `orchestrator` LLM-`deployer`
+заменён **детерминированным staging-раннером** (`src/staging_runner.py`) — его работа была чисто
+механической (запуск staging-сюиты + маппинг exit-кода). LLM-промпт `deployer` остаётся fallback'ом
+под выключенным флагом / для не-self репо и продолжает вести прод-стадию `deploy`. Подробнее —
+[конвейер](tech-pipeline.md) и [карта LLM-консультаций](../architecture/llm-call-sites.md).
+
 ## Человек как седьмая роль
 
 Человек не пишет артефакты конвейера, но принимает два решения, которые не делегированы