C7: venues/brokers visibility (service + CLI + TUI browser) and the newbie help & glossary system

[eaitbrahim]

Per the PRD §5 C7 + O7/O8 (operator additions, 2026-08-19):

Venues/brokers visibility (O7): a brokers service over the existing entry-point registry (discover_brokers()) and BrokerCapabilities: every installed adapter — name, venue id, wired-for-deployment vs optional-dev-venue, session-bound or 24/7, quote currency, asset classes, paper/live endpoints where declared, preview synthesis, supported data feeds — surfaced as keel brokers list (CLI) and a TUI Venues browser under Profile with the selected adapter highlighted and the active deployment's binding shown. Capability display, never key-presence inference (#233-aligned); no secret values ever shown. One service, two front-ends.

Help & glossary (O8): every screen carries a plain-English 'what am I looking at' and every invokable action a 'what will this do' description, written for a newcomer (what a rail IS, what an attestation records, what the promotion gate demands, what the kill switch does, what paper mode means). Definitions live in ONE source (a glossary the TUI help renders and the docs link to); per-screen/per-action help strings land with each menu slice (C2-C5) and are consolidated + audited here. Typed actions' help states explicitly that the prompt cannot be pre-filled.

Acceptance: keel brokers list and the TUI Venues browser show identical information from one service (pinned); every screen/action has help text; glossary has exactly one source with no drifted duplicates.

[eaitbrahim]

Scope addition (2026-08-19, operator): parameter-level help (PRD O8). Every parameter of every rule kind must be explainable in-console — plain-English meaning, what changing it does (and which gate it feeds), type, default, shipped range — e.g. turtle_breakout's entry_lookback/exit_lookback/adx_period/adx_threshold/atr_period/atr_stop_mult/use_macd_confirm/s1_filter/min_volume_filter/volume_ma_period/volume_mult/target_rr/granularity and the other kinds' equivalents. Single-source rule: the truth lives in the rule classes (RULE_REGISTRY constructors) — missing per-param docstrings are added AT THE CLASS and the help renders them by introspection; no hand-maintained duplicate table. Contextually invokable wherever params render (rules list detail, add forms, backtest views).

[eaitbrahim]

C7 complete — merged in PR #406 + the review hardening in PR #407 (three blockers fixed: ? dead in discover behind a dishonest structural test (now AST-based); the glossary's rail entry counting nineteen rails (it is eighteen); and the promotion gate entry INVENTING a DCA-benchmark floor the gate does not have — rewritten to the real axes (four floors + the PBO∧degradation-slope conjunction; pooling's per-parameter-set sample-size-only scope; the overfitting gate not pooled; DCA located in simulate's report). Plus: a raising adapter yields an honest error row instead of killing the brokers listing or the TUI; WIRED_FOR_DEPLOYMENT drift-guarded against the tracked configs; stale help text updated; m/? contracts completed; two more verbatim fiqh pins.)

Delivered: the brokers service (list_installed_brokers — closed capability payload, structural no-secrets guarantee) + keel brokers list [--json] + the TUI Venues browser (selected adapter highlighted, active binding shown; one service, two front-ends, equality-pinned). The help & glossary system: docs/glossary.md as the ONE hand-written definitions file (fiqh terms anchored verbatim to fiqh-basis.md — 11 pinned; params delegated to describe_params, never duplicated), the contextual ? overlay from every console mode via the per-module CONTEXT_HELP registry (35 modes), and the Help menu (glossary / catalog / rule parameters / keys & safety). Gates: 3605 passed, 3 skipped; ruff/mypy clean.