3c53218e19
Expose `ctx.models` to extensions: list() / current() / resolve(spec) / family(model). Lets extension tools select models the same way core does (settings-backed aliases, match preferences, canonical-identity family classification) without reaching into the mutable registry. - types.ts: ExtensionModelQuery interface + `models` on ExtensionContext - model-api.ts: createExtensionModelQuery facade - runner.ts: thread optional Settings; build `models` in createContext() - sdk.ts + agent-session.ts + extension-ui-controller.ts: pass settings / build models on the direct context literals - catalog identity: modelFamilyToken() — coarse canonical-backed lineage token - docs + changelog + tests Implements #2406.