refactor: restructure PM role under skills/kugetsu/pm/

### Changes:

1. **Moved kugetsu-pm to skills/kugetsu/pm/SKILL.md**
   - Simplified to 79 lines (under 100 line target)
   - kugetsu v3.0 with essential PM role definition
   - PM context injected at init/start/continue time

2. **Updated kugetsu_get_pm_context()**
   - Now reads from ~/.kugetsu/pm-agent.md (user custom) first
   - Falls back to skills/kugetsu/pm/SKILL.md (default)

3. **Updated kugetsu-chat v4.0**
   - Added notification checking on status/update queries
   - When user asks "status?", "any updates?", etc., check kugetsu notify list
   - Hybrid approach: PM includes notifications + kugetsu-chat checks on status

4. **Removed old skills/kugetsu-pm/SKILL.md**
   - Replaced by skills/kugetsu/pm/SKILL.md

### Structure:
skills/kugetsu/
├── SKILL.md
├── scripts/kugetsu
├── chat/           # future: kugetsu-chat could move here
│   ├── SKILL.md
│   └── SOUL.md
└── pm/
    └── SKILL.md    # PM role definition (v3.0)

skills/kugetsu-chat/SKILL.md

@@ -5,7 +5,7 @@ license: MIT
 compatibility: Requires Hermes agent with Telegram configured, kugetsu CLI, opencode sessions.
 metadata:
   author: shoko
-  version: "3.0"
+  version: "4.0"
 ---
 
 # kugetsu-chat - REQUIRED SKILL FOR KUGETSU ROUTING
@@ -19,6 +19,7 @@ metadata:
 - Any message containing issue numbers like "#5", "#14", "#123"
 - Any message that looks like a task request or status query
 - Any message containing "pm", "status", "progress", "work on"
+- Any message containing "notify", "updates", "notifications"
 
 **DO NOT USE THIS SKILL for:**
 - "hi", "hello", "hey"
@@ -28,8 +29,6 @@ metadata:
 
 ## Required Actions
 
-When you MUST use this skill:
-
 ### Step 1: Load This Skill
 ```
 /kugetsu-chat
@@ -40,7 +39,15 @@ When you MUST use this skill:
 terminal(command="kugetsu status", timeout=10)
 ```
 
-### Step 3: If initialized, DELEGATE immediately
+### Step 3: Route Based on Message Type
+
+**For STATUS/UPDATE queries:**
+```
+terminal(command="kugetsu notify list", timeout=10)
+```
+Then include notifications in response.
+
+**For TASK requests:**
 ```
 terminal(command="kugetsu delegate '<entire user message>'", timeout=120)
 ```
@@ -49,7 +56,7 @@ terminal(command="kugetsu delegate '<entire user message>'", timeout=120)
 
 ## Delegation Command
 
-The ONLY command you should use for delegation:
+The command for task delegation:
 
 ```bash
 kugetsu delegate '<user message>'
@@ -60,6 +67,16 @@ Example:
 terminal(command="kugetsu delegate 'fix issue #5 in github.com/shoko/kugetsu'", timeout=120)
 ```
 
+## Notification Checking
+
+**When user asks about status/updates, check notifications:**
+
+```bash
+kugetsu notify list
+```
+
+Include any unread notifications in your response.
+
 ## Error Handling
 
 | Status Output | Meaning | Action |
@@ -76,6 +93,11 @@ terminal(command="kugetsu delegate 'fix issue #5 in github.com/shoko/kugetsu'",
 terminal(command="kugetsu delegate '<message>'", timeout=120)
 ```
 
+**CHECK NOTIFICATIONS:**
+```
+terminal(command="kugetsu notify list", timeout=10)
+```
+
 **CHECK STATUS:**
 ```
 terminal(command="kugetsu status", timeout=10)
@@ -88,7 +110,8 @@ terminal(command="kugetsu status", timeout=10)
 
 ## Notes
 
-- ALWAYS use `kugetsu delegate` command (not kugetsu-helper)
+- ALWAYS use `kugetsu delegate` command
 - ALWAYS wrap user message in single quotes inside the command
 - ALWAYS use timeout of at least 120 seconds for delegation
 - kugetsu delegates to the persistent PM agent session created during init
+- PM Agent writes task notifications to `~/.kugetsu/notifications.json`