feat: MCP server v1.2.0 — guide system + read/write guide tools

Adds full guide system to MCP standalone server. System guides (schema,
creating-nodes, edges, dimensions, extract) are bundled and immutable.
Users can create up to 10 custom guides via rah_write_guide. Syncs guide
infrastructure from main repo to OS repo app code.

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

apps/mcp-server-standalone/guides/system/creating-nodes.md

@@ -0,0 +1,38 @@
+---
+name: Creating Nodes
+description: When and how to create nodes. Link field rules. Synthesis patterns.
+immutable: true
+---
+
+# Creating Nodes
+
+## When to Create
+
+- User explicitly asks to save/capture something
+- Extracting insights from existing content (synthesis)
+- Ingesting external content (YouTube, website, PDF)
+
+## Link Field Rules
+
+- **Has link:** Node directly represents external content (YouTube video, website, PDF, article)
+- **No link:** Node is derived/synthesized from existing content (ideas, insights, summaries, questions)
+- Never add a link to synthesis or idea nodes
+
+## Synthesis Pattern
+
+When creating a node derived from existing content:
+1. Create the node WITHOUT a link field
+2. Call `createEdge` to connect it to ALL source nodes
+3. Each edge needs an explanation ("Insight extracted from...", "Synthesized from...")
+
+## Dimension Assignment
+
+- New nodes should be assigned to relevant existing dimensions
+- Check locked/priority dimensions — these auto-assign
+- If no existing dimension fits, create a new one (but prefer existing)
+
+## Description Field
+
+- AI auto-generates a ~1 sentence description after creation
+- Description is used for embeddings and search ranking (5x boost)
+- Format: what is this node about, in plain language