docs: update TODO, CHANGELOG for error handling audit and settings redesign

TODO.md

@@ -2,7 +2,7 @@
 
 ## URGENT
 
-- [ ] **Comprehensive error handling** — Every IPC call, bridge function, and async operation must have proper error handling with user-visible feedback. Current state: most errors are console.error() only (silent to user). Audit needed across all Rust commands (map_err patterns), all frontend bridge calls (missing .catch()), all Svelte components (no error states displayed). Add: ProError enum in agor-pro, toast notifications on failures, loading/error states in all settings components, retry logic for transient failures. Rule 02 (Error Handling) violations are blocking issues.
+- [~] **Comprehensive error handling** — Day 0 foundation shipped: extractErrorMessage, handleError/handleInfraError utilities, error-classifier extended (ipc/database/filesystem), toast rate-limiting. Sprint 1+2 in progress (3 background agents): settings Promise.allSettled migration, Rust AppError enum, bridge/store audit, global unhandledrejection handler. See .tribunal/tribunal-codex-report.md for full plan.
 
 ## Dual-Repo & Commercial
 
@@ -27,6 +27,10 @@
 
 ## Completed
 
+- [x] Settings redesign — 6 modular components replacing 2959-line monolith, theme dropdown fix | Done: 2026-03-18
+- [x] Docs reorganization — subdirectories, 6 new reference docs, bterminal purge | Done: 2026-03-18
+- [x] Svelte warnings fix — 15 warnings resolved (a11y, unused CSS, state_referenced_locally) | Done: 2026-03-18
+- [x] Error handling Day 0 — extractErrorMessage, handleError/handleInfraError, classifier extension, toast rate-limiting | Done: 2026-03-18
 - [x] 3 commercial features (analytics, export, profiles) — Rust + bridge + 14 tests | Done: 2026-03-17
 - [x] bterminal→agor rebrand + dual-repo commercial structure | Done: 2026-03-17
 - [x] Tribunal-codex dual-repo strategy (S-3+S-1 hybrid, 80% confidence) | Done: 2026-03-17