docs: document aidex_global_guideline in README, API reference, and setup

- README: new ## AI Guidelines section with examples and use cases
- README: aidex_global_guideline added to Available Tools table
- MCP-API-REFERENCE: full aidex_global_guideline entry (params, examples, returns) + TOC
- setup.ts: Guidelines row in All Tools table (27→28), Question→Tool examples

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: CSCSoftware

MCP-API-REFERENCE.md

@@ -38,6 +38,7 @@ Complete reference for all AiDex MCP tools.
   - [aidex_global_query](#aidex_global_query)
   - [aidex_global_signatures](#aidex_global_signatures)
   - [aidex_global_refresh](#aidex_global_refresh)
+  - [aidex_global_guideline](#aidex_global_guideline)
 - [Screenshots](#screenshots)
   - [aidex_screenshot](#aidex_screenshot)
   - [aidex_windows](#aidex_windows)
@@ -856,6 +857,33 @@ Update statistics for all registered projects and remove projects whose paths no
 
 ---
 
+### aidex_global_guideline
+
+Store, retrieve, list, or delete persistent AI guidelines and coding conventions. Stored in `~/.aidex/global.db` — available across all projects without requiring `aidex_init`. Perfect for team coding conventions, review checklists, and reusable AI instructions.
+
+**Parameters:**
+
+| Name | Type | Required | Description |
+|------|------|----------|-------------|
+| `action` | string | Yes | `set`, `get`, `list`, or `delete` |
+| `key` | string | for set/get/delete | Guideline name (e.g., `"review"`, `"style"`, `"release"`) |
+| `value` | string | for set | The guideline content to store |
+| `filter` | string | No | Substring filter for `list` action |
+
+**Examples:**
+```json
+{ "action": "set", "key": "review", "value": "Check: error handling, null safety, no magic strings, consistent naming" }
+{ "action": "set", "key": "style", "value": "PascalCase classes, camelCase methods, 4-space indent, XML docs on public APIs" }
+{ "action": "get", "key": "review" }
+{ "action": "list" }
+{ "action": "list", "filter": "code" }
+{ "action": "delete", "key": "old-rule" }
+```
+
+**Returns:** For `get` — key, value, created/updated timestamps. For `list` — all matching guidelines. For `set`/`delete` — confirmation message.
+
+---
+
 ## Screenshots
 
 ### aidex_screenshot

README.md

@@ -409,6 +409,7 @@ aidex_init({ path: "/path/to/your/project" })
 | `aidex_global_query` | Search terms across ALL registered projects |
 | `aidex_global_signatures` | Search methods/types by name across all projects |
 | `aidex_global_refresh` | Update stats and remove stale projects from global DB |
+| `aidex_global_guideline` | Store/retrieve AI guidelines and coding conventions (key-value, global) |
 
 ## Time-based Filtering
 
@@ -531,6 +532,27 @@ aidex_global_status({ sort: "recent" })                                # Most re
 aidex_global_refresh()                                                 # Update stats, remove stale
 ```
 
+## AI Guidelines
+
+Store persistent coding conventions, review checklists, and AI instructions in a single place — shared across all projects.
+
+```
+aidex_global_guideline({ action: "set", key: "review", value: "Always check: error handling, null safety, no hardcoded strings" })
+aidex_global_guideline({ action: "set", key: "style", value: "Use PascalCase for classes, camelCase for methods, 4-space indent" })
+aidex_global_guideline({ action: "get", key: "review" })               # Retrieve a guideline
+aidex_global_guideline({ action: "list" })                             # Show all guidelines
+aidex_global_guideline({ action: "list", filter: "code" })             # Filter by name
+aidex_global_guideline({ action: "delete", key: "old-rule" })          # Remove a guideline
+```
+
+**Use cases:**
+- **Code review checklist**: Tell your AI exactly what to look for every time
+- **Coding conventions**: Store team style rules once, reference them in any project
+- **Release checklist**: Step-by-step process for shipping
+- **Project-agnostic instructions**: No more pasting the same context into every session
+
+Guidelines are stored in `~/.aidex/global.db` — available across all your projects without `aidex_init`. Ask your AI: *"Load the review guideline and apply it to this file."*
+
 ## Screenshots — LLM-Optimized
 
 Take screenshots and **reduce them up to 95%** for LLM context. A typical screenshot goes from ~100 KB to ~5 KB — that's thousands of tokens saved per image.

src/commands/setup.ts

@@ -102,14 +102,16 @@ Do I want to search code?
 | "Have I ever written X?" | \`aidex_global_query term="X" mode="contains"\` |
 | "Which project has class Y?" | \`aidex_global_signatures term="Y" kind="class"\` |
 | "All indexed projects?" | \`aidex_global_status\` |
+| "Store coding convention" | \`aidex_global_guideline action="set"\` |
+| "Load review checklist" | \`aidex_global_guideline action="get"\` |
 
 ### Search Modes
 
 - **\`exact\`** (default): Finds only the exact identifier — \`log\` won't match \`catalog\`
 - **\`contains\`**: Finds identifiers containing the term — \`render\` matches \`preRenderSetup\`
 - **\`starts_with\`**: Finds identifiers starting with the term — \`Update\` matches \`UpdatePlayer\`, \`UpdateUI\`
 
-### All Tools (27)
+### All Tools (28)
 
 | Category | Tools | Purpose |
 |----------|-------|---------|
@@ -118,6 +120,7 @@ Do I want to search code?
 | Overview | \`aidex_summary\`, \`aidex_tree\`, \`aidex_describe\`, \`aidex_files\` | Entry points, file tree, file listing by type |
 | Cross-Project | \`aidex_link\`, \`aidex_unlink\`, \`aidex_links\`, \`aidex_scan\` | Link dependencies, discover projects |
 | Global Search | \`aidex_global_init\`, \`aidex_global_query\`, \`aidex_global_signatures\`, \`aidex_global_status\`, \`aidex_global_refresh\` | Search across ALL projects |
+| Guidelines | \`aidex_global_guideline\` | Persistent AI instructions & conventions (key-value, global) |
 | Sessions | \`aidex_session\`, \`aidex_note\` | Track sessions, leave notes (with searchable history) |
 | Tasks | \`aidex_task\`, \`aidex_tasks\` | Built-in backlog with priorities, tags, auto-logged history |
 | Screenshots | \`aidex_screenshot\`, \`aidex_windows\` | Cross-platform screen capture (no index needed) |