feat(rah-light): replace workflows with guides system

- Remove entire workflow system (API routes, services, tools, components)
- Add guides system from main ra-h repo (for external agent integration)
- Update pane types: 'workflows' → 'guides' throughout
- Update LeftToolbar to show guides icon instead of workflows
- Update SettingsModal with GuidesViewer tab
- Add GuidesPane for browsing guides in main UI
- Clean up prompts to remove workflow references
- Update tool registry to remove workflow tools
- Add gray-matter package for frontmatter parsing

Guides are essential for RA-H Light as they help external agents
(via MCP) understand the knowledge base context and usage patterns.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/config/guides/integrate.md

@@ -0,0 +1,71 @@
+---
+name: Integrate
+description: Full analysis — find connections across the knowledge graph, create edges, and document an integration analysis.
+---
+
+# Integrate
+
+Find meaningful connections across the knowledge graph, create edges, and append an Integration Analysis.
+
+## Steps
+
+1. **Retrieve & Understand**
+   - Call `getNodesById` for the focused node
+   - Identify: what type of thing is this? (person, project, paper, idea, video, etc.)
+   - Extract key entities: names, projects, concepts, techniques
+   - Note the core insight in one sentence
+
+2. **Search for Connections**
+   Search the database using entities from step 1:
+
+   a) Structural connections:
+      - Names mentioned → `queryNodes` to find nodes about those people
+      - Projects/tools mentioned → `queryNodes` to find those nodes
+
+   b) Thematic connections:
+      - Use `searchContentEmbeddings` with key concepts
+      - Look for shared themes, complementary ideas, contradictions
+
+   Target: 3-5 strong connections (quality over quantity)
+
+3. **Create Edges**
+   For each connection found, call `createEdge`:
+   - `from_node_id`: the focused node ID
+   - `to_node_id`: the connected node ID
+   - `explanation`: "why this connection matters"
+
+   Direction rule: write the explanation so it reads FROM → TO.
+   Examples:
+   - Insight → Source: "Came from / inspired by"
+   - Episode → Podcast: "Episode of this podcast"
+
+   The tool handles duplicates gracefully — if edge exists, it returns an error and you continue.
+
+   Create 3-5 edges total.
+
+4. **Document in Content**
+   Call `updateNode` ONCE using the `content` field with ONLY this new section:
+
+   ```
+   ---
+   ## Integration Analysis
+
+   [2-3 sentences: what this is, why it matters, core insight]
+
+   **Connections:**
+   - [NODE:123:"Title"] — [why connected]
+   - [NODE:456:"Title"] — [why connected]
+   ```
+
+   Use `updates.content` (NOT chunk). Send ONLY the new section. The tool appends automatically.
+
+5. **Return Summary**
+   Reply with: Task / Actions / Result / Nodes / Follow-up (≤100 words)
+
+## Rules
+
+- Keep total tool calls ≤ 12
+- Create edges BEFORE documenting (step 3 before step 4)
+- Call `updateNode` exactly once
+- Adapt to any node type
+- Use `think` at any point if you need to plan your approach