docs: document run_events schema, workspace_id filter behavior, history unbounded output, pricing_import_audit fields, and unused core deps

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Summary

Documentation improvements triggered by the push to main (troubleshooting guide + DEVELOPMENT.md expansion). This PR fills specific knowledge gaps identified by reading the source code against the existing docs.

Why

The recently landed docs (#32) added broad troubleshooting coverage. In reviewing the full docs-vs-source alignment, several concrete but underdocumented behaviors were found that could mislead integrators or operators.

Changes

• docs/operations-and-policy.md — Added run_events column layout table: documents which RunEvent fields are stored as indexed top-level columns (filterable by query_runs) vs. which live only inside event_json. Clarifies that workspace_id, labels, request, and usage.* fields are in event_json only and are not diff-query filters.

• docs/http-api.md — Clarified workspace_id field description: the field is stored with the event but is not used as a query filter in diff or promote/rollback paths (diff queries filter on release_id, tenant_id, task_id, and environment only).

• docs/cli.md — Added note to flightdeck release history: the command returns all matching rows with no limit, unlike GET /v1/actions which accepts a limit query parameter (1–500, default 50).

• docs/release-artifact.md — Expanded pricing_import_audit section: replaced the prose field list with a structured table (all 10 columns with types and descriptions) and added a sqlite3 query example for inspecting the audit trail directly.

• DEVELOPMENT.md — Added note under Package extras: sqlalchemy, aiosqlite, and rich appear as core dependencies in pyproject.toml but are not imported by src/flightdeck/ (the package uses stdlib sqlite3 and plain Click output). Documents these as leftover prototype entries scheduled for removal.

Validation

• uv sync --frozen --extra dev
• uv run python -m ruff check src tests — all checks passed
• uv run python -m pytest — 94 passed
• uv run python scripts/generate_schemas.py then git diff --exit-code schemas/ — clean (no model changes)
• Web/Playwright: not applicable (no web/ changes)

Schema / Storage Impact

• None

Risk

Documentation-only. No code changes; no behavior changes; no schema drift.

Notes

All changes verified against src/flightdeck/storage.py (column definitions, query_runs WHERE clauses), src/flightdeck/cli/main.py (history command uses storage.list_release_actions with no limit), and src/flightdeck/server/routes/read.py (GET /v1/actions uses action_limit=limit).