[LinuxDevil]

What changed

• New agentTabs.ts (React-free): AGENT_TABS, AgentTab, AGENT_TAB_LABELS, BUILT_AGENT_TABS (only canvas built), isAgentTab, agentTabPath, and agentRedirect (legacy /agents/:id and unbuilt/unknown tabs redirect to /agents/:id/canvas, hash query preserved).
• routeTable.ts: ScreenId gains agentList / agentDetail; /agents is now the agents list, /agents/:id/canvas the builder, /agents/:id/:tab the detail route.
• routes.tsx: useScreen applies agentRedirect with replace before the unknown-route fallback; SCREENS gains both entries (rendered inside ScreenFrame).
• New placeholder AgentListScreen (+ css, EmptyState for an empty workspace) and AgentDetailRoute (returns null until A05).
• agentRoute.ts: agentRouteId accepts all three agent URL shapes; agentPath always returns the canvas URL; RouteSync drops canonical.
• useAgentRouteSync.ts: unknown id falls back to /agents (the list); follow-the-open-agent navigates to the canvas URL.
• LeftRail card click navigates to agentPath(id); CommandPalette open agent navigates to agentTabPath(id, 'overview').
• Unit tests updated plus new agentTabs.test.ts and AgentListScreen.test.tsx; e2e specs updated (studio, studioUx, revamp, a11y, narrow, docShots).

How it was tested

• npm test --workspace apps/agent-forge -- --run: 973 tests pass (90 files).
• npm run typecheck, npm run lint, npm run typecheck:server, npm run test:server (1121 tests) for apps/agent-forge: pass.
• Root npx tsc --noEmit, npm run lint: pass.
• npm run test:coverage: passes after building packages/create-lousho and normalizing checked-out CRLF template READMEs locally (uncommitted environmental fixes).
• npm run fallow: clean for this change (3 new contract exports annotated for later tickets); the 6 duplicate-code groups it reports are identical on main.
• npm run docs:ratchet, npm run api:check, npm run docs:llms:check, npm run size-check: pass.
• npm run test:e2e:studio: 116 passed; 7 remaining failures are in UI agent-creation flows (server rejects some spec PUTs with validation errors), under investigation — routing, redirects, list fallback, reload persistence and axe scans all pass.

Acceptance criteria

• #/agents shows the list placeholder with header "Agents"; the nav item Agents is active.
• #/agents/<id> lands on #/agents/<id>/canvas with replace (Back does not return to the legacy URL).
• #/agents/<id>/canvas opens the builder for that agent; reload keeps it.
• #/agents/<id>/overview (and any unbuilt or unknown tab) redirects to canvas until that tab's ticket lands.
• Rail clicks and "Open agent X" in the palette land on the new URLs; an unknown id in the builder falls back to #/agents.
• The unsaved default agent is reachable at #/agents/untitled-agent/canvas.

Generated with Devin