fix: Enforce min_chunk_size in RAG chunker

- Filter out chunks smaller than min_chunk_size (default 100 tokens)
- Exception: Keep all chunks if entire document is smaller than target size
- All 15 tests passing (100% pass rate)

Fixes edge case where very small chunks (e.g., 'Short.' = 6 chars) were
being created despite min_chunk_size=100 setting.

Test: pytest tests/test_rag_chunker.py -v

src/skill_seekers/sync/notifier.py

@@ -0,0 +1,144 @@
+"""
+Notification system for sync events.
+"""
+
+import os
+import requests
+from typing import Optional, List
+from .models import WebhookPayload
+
+
+class Notifier:
+    """
+    Send notifications about sync events.
+
+    Supports:
+    - Webhook (HTTP POST)
+    - Slack (via webhook)
+    - Email (SMTP) - TODO
+    - Console (stdout)
+
+    Examples:
+        notifier = Notifier()
+
+        payload = WebhookPayload(
+            event="change_detected",
+            skill_name="react",
+            changes=report
+        )
+
+        notifier.send(payload)
+    """
+
+    def __init__(
+        self,
+        webhook_url: Optional[str] = None,
+        slack_webhook: Optional[str] = None,
+        email_recipients: Optional[List[str]] = None,
+        console: bool = True
+    ):
+        """
+        Initialize notifier.
+
+        Args:
+            webhook_url: Webhook URL for HTTP notifications
+            slack_webhook: Slack webhook URL
+            email_recipients: List of email recipients
+            console: Whether to print to console
+        """
+        self.webhook_url = webhook_url or os.getenv('SYNC_WEBHOOK_URL')
+        self.slack_webhook = slack_webhook or os.getenv('SLACK_WEBHOOK_URL')
+        self.email_recipients = email_recipients or []
+        self.console = console
+
+    def send(self, payload: WebhookPayload):
+        """
+        Send notification via all configured channels.
+
+        Args:
+            payload: Notification payload
+        """
+        if self.console:
+            self._send_console(payload)
+
+        if self.webhook_url:
+            self._send_webhook(payload)
+
+        if self.slack_webhook:
+            self._send_slack(payload)
+
+        if self.email_recipients:
+            self._send_email(payload)
+
+    def _send_console(self, payload: WebhookPayload):
+        """Print to console."""
+        print(f"\n📢 {payload.event.upper()}: {payload.skill_name}")
+
+        if payload.changes:
+            changes = payload.changes
+            if changes.has_changes:
+                print(f"   Changes detected: {changes.change_count}")
+                if changes.added:
+                    print(f"   ✅ Added: {len(changes.added)} pages")
+                if changes.modified:
+                    print(f"   ✏️  Modified: {len(changes.modified)} pages")
+                if changes.deleted:
+                    print(f"   ❌ Deleted: {len(changes.deleted)} pages")
+            else:
+                print("   No changes detected")
+
+    def _send_webhook(self, payload: WebhookPayload):
+        """Send to generic webhook."""
+        try:
+            response = requests.post(
+                self.webhook_url,
+                json=payload.dict(),
+                headers={'Content-Type': 'application/json'},
+                timeout=10
+            )
+            response.raise_for_status()
+            print(f"✅ Webhook notification sent to {self.webhook_url}")
+        except Exception as e:
+            print(f"❌ Failed to send webhook: {e}")
+
+    def _send_slack(self, payload: WebhookPayload):
+        """Send to Slack via webhook."""
+        try:
+            # Format Slack message
+            text = f"*{payload.event.upper()}*: {payload.skill_name}"
+
+            if payload.changes and payload.changes.has_changes:
+                changes = payload.changes
+                text += f"\n• Changes: {changes.change_count}"
+                text += f"\n• Added: {len(changes.added)}"
+                text += f"\n• Modified: {len(changes.modified)}"
+                text += f"\n• Deleted: {len(changes.deleted)}"
+
+                # Add URLs of changed pages
+                if changes.modified:
+                    text += "\n\n*Modified Pages:*"
+                    for change in changes.modified[:5]:  # Limit to 5
+                        text += f"\n• {change.url}"
+                    if len(changes.modified) > 5:
+                        text += f"\n• ...and {len(changes.modified) - 5} more"
+
+            slack_payload = {
+                "text": text,
+                "username": "Skill Seekers Sync",
+                "icon_emoji": ":books:"
+            }
+
+            response = requests.post(
+                self.slack_webhook,
+                json=slack_payload,
+                timeout=10
+            )
+            response.raise_for_status()
+            print("✅ Slack notification sent")
+        except Exception as e:
+            print(f"❌ Failed to send Slack notification: {e}")
+
+    def _send_email(self, payload: WebhookPayload):
+        """Send email notification."""
+        # TODO: Implement SMTP email sending
+        print(f"📧 Email notification (not implemented): {self.email_recipients}")