feat(tui): venues visibility and the help & glossary system (#394 C7)

[eaitbrahim]

Closes the console PRD's C7 slice: O7 (venues/brokers visibility, service-first) and O8 (the newbie help & glossary system). Test-first: the new suites were written red (tests/commands/test_brokers.py, tests/commands/test_help_console.py — both failed at import before a line of implementation), then made green.

The brokers service (O7) — one service, two front-ends

keel/commands/brokers.py::list_installed_brokers() walks the entry-point registry (discover_brokers()), constructs each adapter credential-less, and renders one frozen BrokerInfo row per installed adapter:

name, venue, deployment ("wired-for-deployment" | "optional-dev-venue"),
session_bound, quote_currencies, asset_classes, supported_orders,
preview ("native" | "synthesized" | "none"), supports_fee_summary,
declared_endpoints, supported_data_feeds, package_version

• Every field derives from the adapter's own declarations (capabilities(), the new DECLARED_ENDPOINTS/DECLARED_DATA_FEEDS on AlpacaAdapter — derived from TRADING_HOSTS/SUPPORTED_DATA_FEEDS, never a second list). Pinned: the payload fields equal the adapters' declarations, per field.
• No secrets, no key-presence inference (Venue visibility must be capability-based, not key-presence-based — a read-only key looks identical to a working one #233-aligned): the field set is closed and pinned by test; the payload is JSON-scanned for secret vocabulary; the screen and CLI both carry the shared NO_KEY_INFERENCE_LINE.
• Wired vs optional is ONE explicit constant (WIRED_FOR_DEPLOYMENT = {coinbase, alpaca}) with its reasoning in place — no registry signal carries it.
• Front-ends: keel brokers list (+ --json following status --json's convention, no disclaimer after JSON; the README's trademark line in the docstring) and the TUI Venues browser under Profile (console.build_venues_lines): same payload via the service's shared capability_facts wording, the SELECTED adapter highlighted [selected], the active deployment's binding (config+db pair; endpoint/data feed where the venue declares them) named. The one-payload/two-front-ends equality is pinned by test; the browser's facts are read once per entry, never per poll.

The glossary (O8) — one source, anchored

docs/glossary.md is the ONE new hand-written file and the only place console terms are defined. Seeded with the console's needed terms (rail; attestation + instrument attestation; exemption; screening; promotion gate; paper/live mode; kill switch; autonomy; qabd; riba; gharar; maysir/maisir alias; purification; session-bound venue; market clock; trust window; DCA benchmark; granularity; trials ledger). Design as built:

• Fiqh terms' definitions are verbatim passages of docs/fiqh-basis.md, each carrying the document's exact section heading as its citation; gharar says "not stated in docs/fiqh-basis.md" exactly as C3's shariah screen does. Pinned against the document (spot-pins: qabd, riba word-for-word) and pinned equal to compliance_console.VOCABULARY, so the two surfaces cannot drift.
• The TUI renders it bounded-read and mtime-cached (the research readers' discipline — MAX_GLOSSARY_BYTES, cached_glossary per (path, mtime_ns)); an absent file (an installed deployment has no docs/ checkout) is a calm empty state naming the path.
• Rule parameters are never duplicated: the Help menu's parameter view renders rules.describe_params (the classes' own docstrings/defaults/types/choices, by introspection) — pinned to contain describe_params' actual doc strings for turtle_breakout's full param set; the glossary's granularity entry points there too.

The contextual help registry (O8)

Each console module owns its screens' rows (CONTEXT_HELP: plain (subject, description) pairs keyed by mode — text lives with the module that owns the screen); keel/commands/help_console.py is the registry (CONSOLE_MODES + lazy mode→owner resolution) and renderer. ? opens the current mode's overlay from every console mode and q/Esc/? returns to the screen it was opened from — pinned three ways: the registry is total over run_live's dispatched modes, a structural scan asserts every mode == branch in run_live handles ord("?"), and behavioral run_live tests drive the overlay open/close. The typed actions' help states the prompt cannot be pre-filled (pinned: ≥4 occurrences, on the trading/compliance/strategy screens). The Help menu entry becomes a real sub-menu: glossary · screens & actions (the consolidated catalog) · rule parameters · keys & safety (the pre-C7 help screen, kept whole).

Gates

• uv run pytest -q — 3598 passed, 3 skipped
• uv run ruff check keel tests packages — clean
• uv run mypy — clean (277 files)

Fixes #394