feat(FN-3040): make peer exchange shutdown deterministic and improve dashbo

This merge lands seven features and fixes across the dashboard and engine. Notable changes: restructured TodoView rows with improved action row styling, added `/clear` command to Chat and QuickChat, persisted session banner dismissals with a hide-banner setting, made peer exchange shutdown determini

Fusion-Task-Id: FN-3040

docs/architecture.md

@@ -358,6 +358,10 @@ Implemented in `agent-heartbeat.ts`:
 ### Node/mesh runtime services
 - `NodeHealthMonitor` (`node-health-monitor.ts`) — remote node liveness/metrics checks
 - `PeerExchangeService` (`peer-exchange-service.ts`) — peer sync orchestration
+- Process lifecycle ownership:
+  - `fn serve` / `fn dashboard` start a single process-level `PeerExchangeService` and stop it during shutdown.
+  - `CentralCore.startDiscovery()` is invoked from CLI startup only after HTTP bind completes so discovery advertises the actual listening port.
+  - `InProcessRuntime` stays project-scoped and intentionally does not own mesh startup/shutdown.
 
 ### Remote access runtime
 

docs/multi-project.md

@@ -31,9 +31,14 @@ Core tables:
 
 Per-project task data remains in each repo’s `.fusion/fusion.db`.
 
-Peer/mesh coordination spans core + engine:
-- `NodeDiscovery` and `NodeConnection` in `@fusion/core` handle discovery and remote node connectivity/auth.
+Peer/mesh coordination spans core + engine, with startup ownership in CLI process entrypoints:
+- `NodeDiscovery` and `NodeConnection` in `@fusion/core` handle discovery and remote node connectivity/auth primitives.
 - `PeerExchangeService` in `@fusion/engine` coordinates node-to-node sync/exchange workflows.
+- `runServe()` and `runDashboard()` (CLI) own process-level mesh service lifecycle:
+  - start one process-wide `PeerExchangeService` instance
+  - call `CentralCore.startDiscovery()` only after the HTTP server is listening and the real bound port is known
+  - stop peer exchange + discovery on shutdown
+- `InProcessRuntime` remains project-scoped (scheduler/executor/heartbeat/missions) and does **not** start mesh services, which avoids one peer-exchange instance per project.
 
 ## Registering and Managing Projects
 

docs/settings-reference.md

@@ -73,6 +73,8 @@ Defaults from `DEFAULT_GLOBAL_SETTINGS`; key scope from `GLOBAL_SETTINGS_KEYS`.
 | `settingsSyncInterval` | `number` | `900000` | Automatic sync interval in ms. Valid values: `300000`, `900000`, `1800000`, `3600000`. |
 | `settingsSyncConflictResolution` | `"last-write-wins" \| "always-ask" \| "keep-local" \| "keep-remote"` | `"last-write-wins"` | Conflict strategy for divergent synced settings. |
 | `dashboardCurrentNodeId` | `string` | `undefined` | Currently selected dashboard node ID. Restores the last-viewed node on fresh browser/PWA sessions. `undefined` means viewing the local node. |
+
+> Mesh lifecycle note: settings sync is executed by the process-level `PeerExchangeService` started by `fn serve`/`fn dashboard`. `InProcessRuntime` does not instantiate settings-sync mesh services per project.
 | `dashboardCurrentProjectIdByNode` | `Record<string, string>` | `undefined` | Map of node ID to last-selected project ID. Use key `"local"` for the local node. Persists project context across browser restarts and PWA sessions. |
 | `researchGlobalDefaults` | `ResearchGlobalDefaults` | `{ searchProvider: undefined, synthesisProvider: undefined, synthesisModelId: undefined, enabledSources: { webSearch: true, pageFetch: true, github: false, localDocs: true, llmSynthesis: true }, maxSourcesPerRun: 20, defaultExportFormat: "markdown" }` | Global Research defaults shared by all projects. Project overrides come from `researchSettings`. |
 | `experimentalFeatures` | `Record<string, boolean>` | `{}` | Global-scoped experimental feature flags. Includes `experimentalFeatures.researchView` for standalone Research route visibility. |