feat: add graph-aware recall, auto-linking, and multi-tool hooks (#91)

- Auto-link memories by embedding similarity (>0.75 cosine) with
  bidirectional backrefs at store time (auto_link.rs)
- Graph-aware recall: expand results 1-hop via related_ids with
  0.5× score discount
- Add hooks support for Gemini CLI (SessionStart, BeforeTool,
  AfterTool, PreCompress, BeforeAgent) in ~/.gemini/settings.json
- Add hooks support for Codex CLI (SessionStart, PreToolUse,
  PostToolUse, UserPromptSubmit) in ~/.codex/hooks.json
- Add hooks + MCP support for Copilot CLI
  (~/.copilot/mcp-config.json + .github/hooks/icm.json)
- Adapt hook handlers for cross-tool field names
  (run_shell_command, prompt, input)
- Rename inject_claude_hook → inject_settings_hook (generic)
- expand_with_neighbors() in store for graph traversal

Author: pszymkowiak

.github/hooks/icm.json

@@ -0,0 +1,33 @@
+{
+  "version": 1,
+  "hooks": {
+    "sessionStart": [
+      {
+        "type": "command",
+        "bash": "/Users/patrick/dev/rtk-ai/icm/target/release/icm hook start",
+        "timeoutSec": 10
+      }
+    ],
+    "preToolUse": [
+      {
+        "type": "command",
+        "bash": "/Users/patrick/dev/rtk-ai/icm/target/release/icm hook pre",
+        "timeoutSec": 5
+      }
+    ],
+    "postToolUse": [
+      {
+        "type": "command",
+        "bash": "/Users/patrick/dev/rtk-ai/icm/target/release/icm hook post",
+        "timeoutSec": 10
+      }
+    ],
+    "userPromptSubmitted": [
+      {
+        "type": "command",
+        "bash": "/Users/patrick/dev/rtk-ai/icm/target/release/icm hook prompt",
+        "timeoutSec": 10
+      }
+    ]
+  }
+}

AGENTS.md

@@ -0,0 +1,32 @@
+<!-- icm:start -->
+## Persistent memory (ICM) — MANDATORY
+
+This project uses [ICM](https://github.com/rtk-ai/icm) for persistent memory across sessions.
+You MUST use it actively. Not optional.
+
+### Recall (before starting work)
+```bash
+icm recall "query"                        # search memories
+icm recall "query" -t "topic-name"        # filter by topic
+icm recall-context "query" --limit 5      # formatted for prompt injection
+```
+
+### Store — MANDATORY triggers
+You MUST call `icm store` when ANY of the following happens:
+1. **Error resolved** → `icm store -t errors-resolved -c "description" -i high -k "keyword1,keyword2"`
+2. **Architecture/design decision** → `icm store -t decisions-{project} -c "description" -i high`
+3. **User preference discovered** → `icm store -t preferences -c "description" -i critical`
+4. **Significant task completed** → `icm store -t context-{project} -c "summary of work done" -i high`
+5. **Conversation exceeds ~20 tool calls without a store** → store a progress summary
+
+Do this BEFORE responding to the user. Not after. Not later. Immediately.
+
+Do NOT store: trivial details, info already in CLAUDE.md, ephemeral state (build logs, git status).
+
+### Other commands
+```bash
+icm update <id> -c "updated content"     # edit memory in-place
+icm health                                # topic hygiene audit
+icm topics                                # list all topics
+```
+<!-- icm:end -->