docs: finish splitting README into component docs

README is now just an overview with links. Component docs:
- docs/memory.md: store design, algorithms, config, CLI reference
- docs/hooks.md: Claude Code integration setup
- docs/daemon.md, docs/notifications.md: from previous commit

docs/hooks.md

@@ -0,0 +1,49 @@
+# Hooks
+
+Hooks integrate poc-memory into Claude Code's session lifecycle.
+Two hook binaries fire on session events, providing memory recall
+and notification delivery.
+
+## Setup
+
+Configured in `~/.claude/settings.json`:
+
+```json
+{
+  "hooks": {
+    "UserPromptSubmit": [{"hooks": [
+      {"type": "command", "command": "memory-search", "timeout": 10},
+      {"type": "command", "command": "poc-hook", "timeout": 5}
+    ]}],
+    "PostToolUse": [{"hooks": [
+      {"type": "command", "command": "poc-hook", "timeout": 5}
+    ]}],
+    "Stop": [{"hooks": [
+      {"type": "command", "command": "poc-hook", "timeout": 5}
+    ]}]
+  }
+}
+```
+
+## memory-search (UserPromptSubmit)
+
+Fires on every user prompt. Two modes:
+
+1. **First prompt or post-compaction**: loads full memory context
+   via `poc-memory load-context` — journal entries, identity nodes,
+   orientation file, configured context groups.
+
+2. **Every prompt**: keyword search over the knowledge graph,
+   returns relevant memories as `additionalContext`. Deduplicates
+   across the session to avoid repeating the same memories.
+
+## poc-hook (UserPromptSubmit, PostToolUse, Stop)
+
+Signals session activity to `poc-daemon` and delivers pending
+notifications:
+
+- **UserPromptSubmit**: signals user activity, drains pending
+  notifications into `additionalContext`
+- **PostToolUse**: signals assistant activity (tool use implies
+  the session is active)
+- **Stop**: signals session end, triggers experience-mine