wave 2 (platform stream): settings storage & plumbing foundation (P2)
- src/core/settings.ts: versioned DELTA record schema + sanitizer (unknown keys preserved)
— general/chat/agent{models,tools,prompts}/appearance/graph sections
- src/core/settings-resolution.ts: pure resolveSettings (factory defaults → user delta),
extraction/graph-context channel predicates
- src/store/settings.ts + prompt-overrides.ts: SettingsStore/PromptOverrideStore adapters
wired through stores.ts (effectiveSettings() fresh per call); lazy migration of
default-settings.json into record.chat
- app/api/settings/** routes (record, section bodies, prompt overrides per segment)
- chat-handler: graph gates at trigger call-sites + toolToggles injection seam
- config.ts: SETTINGS_FILE + PROMPTS_OVERRIDE_DIR paths
587/587 tests; typecheck/lint/build clean