Make CLI, doctor, and operator documentation an executable contract

[jmcte]

Problem

Operator docs and runtime behavior disagree:

• mpi doctor --json is documented but fails because --json is only global.
• Runbook examples place global --db after subcommands and fail.
• Live configuration names differ between the runbook and runtime.
• Docs imply copying .env.example is sufficient, but runtime reads process environment and has no dotenv loader.
• Doctor reports live access ok based only on variable presence.
• The live-adapter example passes a nonexistent SyncBatch.next_cursor.
• Phase status marks modules “done” even when they are contract-only or stubs.

Relevant code/docs

• src/mailplus_intelligence/cli.py:292-400
• src/mailplus_intelligence/doctor.py:38-153
• src/mailplus_intelligence/live_adapter.py:33-85
• src/mailplus_intelligence/sync.py:18-25
• docs/quickstart.md
• docs/ops-runbooks.md
• docs/integration/live-mailplus-adapter.md
• docs/live-adapter.md
• docs/phase2-planning.md
• docs/bootstrap/next-steps.md

Scope

• Choose and enforce a consistent common-option model; common flags should work in documented positions or docs must use the supported canonical order.
• Normalize live credential names across code, .env.example, doctor, and runbooks.
• Either explicitly support dotenv loading or state that operators must export variables/process-inject them.
• Split doctor live status into configured, reachable, authenticated, and sync-capable.
• Correct SyncBatch examples and cursor terminology.
• Replace binary “done” claims with fixture-complete, contract-only, integrated, and production-verified.
• Add an executable documentation smoke test for every command block in the quickstart/runbook that is expected to run in fixture mode.

Non-goals

• Do not implement live network access here.
• Do not add real credentials or hostnames to fixtures.
• Do not claim connectivity from environment-variable presence.

Acceptance criteria

• Every fixture-mode command documented in quickstart/runbooks is executed verbatim in CI.
• JSON and database flags behave consistently in documented positions.
• Credential names and setup instructions agree everywhere.
• Doctor distinguishes configuration from real capability.
• Live adapter examples instantiate current public types correctly.
• Phase/status docs accurately distinguish stubs from integrated behavior.
• Stale bootstrap/release wording is removed or updated.
• Failure messages include a concrete next step without exposing secrets.

Validation

bash scripts/ci/run-fast-checks.sh
# run the new docs/CLI smoke harness
mpi --help
mpi doctor --json

The PR should include captured output for the canonical quickstart path.

Parent

Part of #98.