feat: add start-here master guide + enriched tool descriptions

Adds immutable "start-here" system guide as the master orientation doc
for agents. Enriches all tool descriptions with key rules at point of
use so agents can execute simple tasks without reading guides.

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

apps/mcp-server-standalone/guides/system/start-here.md

@@ -0,0 +1,60 @@
+---
+name: Start Here
+description: Master orientation. Read this first when tasks are ambiguous or complex.
+immutable: true
+---
+
+# Start Here
+
+This is the user's personal knowledge graph — a local SQLite database of nodes connected by edges, organized into dimensions.
+
+## Nodes
+
+Every piece of knowledge is a node. Key fields:
+
+- **title** — Clear, descriptive, max 160 chars. Should stand alone as a meaningful label.
+- **description** — One-sentence summary. Powers search and AI understanding. Auto-generated if omitted.
+- **content** — Your notes, analysis, commentary. This is where synthesis lives.
+- **chunk** — Verbatim source text (transcript, article body, full quote). Kept separate from your analysis in content.
+- **link** — ONLY for external content (URLs, YouTube, articles, PDFs). Omit for ideas, synthesis, or anything derived from existing nodes.
+- **dimensions** — 1–5 categories. Always call rah_list_dimensions first and use existing ones.
+
+Two types of nodes:
+- **External content** (has link) — articles, videos, papers, tweets. The link points to the source.
+- **Synthesis/ideas** (no link) — insights, connections, personal thinking. Create edges back to source nodes instead.
+
+## Edges
+
+Connections between nodes. The most valuable part of the graph — they represent understanding, not proximity.
+
+- Every edge needs an **explanation** — a human-readable sentence explaining WHY this connection exists
+- **Direction matters** — reads as: source → [explanation] → target. Example: node "Alice" → "invented this technique" → node "Technique X"
+- Edge types are inferred from the explanation — don't set them manually
+- Create edges after synthesis, when relationships surface, or when a guide instructs you to
+
+## Dimensions
+
+Categories that organize nodes. Two kinds:
+
+- **Priority (locked)** — core categories the user actively maintains (e.g., "research", "person", "idea", "entity")
+- **Non-priority** — secondary tags applied when relevant (e.g., "philosophy", "venture", "ai")
+- Naming: lowercase, singular form, concise, no overlapping names
+- Every dimension needs a description explaining its purpose
+- Check existing dimensions before creating new ones — avoid near-duplicates
+
+## Key Conventions
+
+1. **Search before creating** — always call rah_search_nodes to check for duplicates
+2. **Content appends, dimensions replace** — when updating a node, new content is added below existing content; dimensions are fully replaced with the new array
+3. **Hub nodes** are the most-connected nodes — they represent the user's major themes and interests
+4. **Proactively save valuable information** — when you spot something worth preserving in a conversation, offer to add it
+5. **Quality over quantity** — one well-titled, well-connected node is better than five shallow ones
+
+## Guides
+
+There are two kinds of guides available via rah_list_guides:
+
+- **System guides (immutable)** — reference documentation maintained by RA-H. Cover schema, node creation, edges, dimensions, and content extraction. Always available, cannot be modified.
+- **User guides (custom)** — created by the user for their own workflows, preferences, and procedures. Can be created, edited, and deleted via rah_write_guide / rah_delete_guide.
+
+Call rah_list_guides to see what's available, then rah_read_guide to load any guide you need.