feat(workspaces): add unified /workspace lifecycle, target persistence, and workspace-scoped RAG

- Introduce  command for CLI and TUI with create/activate, list, info, note, clear, export, import, and help actions
- Persist workspace state via  marker and enriched  (targets, operator notes, last_active_at, last_target)
- Restore  on workspace activation and sync it to UI banner, agent state, and CLI output
- Enforce target normalization and ensure  always exists in workspace targets
- Route loot output to  when a workspace is active
- Prefer workspace-local knowledge paths for indexing and RAG resolution
- Persist RAG indexes per workspace and load existing indexes before re-indexing
- Add deterministic workspace export/import utilities (excluding caches)
- Integrate workspace handling into TUI slash commands with modal help screen

workspaces/.active

@@ -0,0 +1 @@
+Test2

workspaces/Test1/meta.yaml

@@ -0,0 +1,8 @@
+name: Test1
+created_at: '2026-01-19T08:05:29Z'
+targets:
+- 192.168.0.4
+last_active_at: '2026-01-19T08:28:24Z'
+operator_notes: ''
+tool_runs: []
+last_target: 192.168.0.4

workspaces/Test2/meta.yaml

@@ -0,0 +1,8 @@
+name: Test2
+created_at: '2026-01-19T08:05:55Z'
+targets:
+- 192.168.0.165
+last_active_at: '2026-01-19T08:28:27Z'
+operator_notes: ''
+tool_runs: []
+last_target: 192.168.0.165