feat: Add in-app help system with HelpIcon component

Add contextual help icons throughout the UI to improve feature
discoverability. Users can click (?) icons to see explanations
with examples for settings they might not understand.

- HelpIcon component with click-to-open popover
- Centralized help content registry in /content/help/
- FeatureTip component for dismissible contextual tips
- Help added to: alert delay, AI endpoints, update channel

docs/API.md

@@ -6,7 +6,7 @@ Pulse provides a comprehensive REST API for automation and integration.
 
 ## 🔐 Authentication
 
-All API requests require authentication via one of the following methods:
+Most API requests require authentication via one of the following methods:
 
 **1. API Token (Recommended)**
 Pass the token in the `X-API-Token` header.
@@ -22,6 +22,19 @@ curl -H "Authorization: Bearer your-token" http://localhost:7655/api/health
 **3. Session Cookie**
 Standard browser session cookie (used by the UI).
 
+Public endpoints include:
+- `GET /api/health`
+- `GET /api/version`
+
+## 🔏 Scopes and Admin Access
+
+Some endpoints require admin privileges and/or scopes. Common scopes include:
+- `monitoring:read`
+- `settings:read`
+- `settings:write`
+
+Endpoints that require admin access are noted below.
+
 ---
 
 ## 📡 Core Endpoints
@@ -73,6 +86,10 @@ Validate credentials before saving.
 Returns time-series data for CPU, Memory, and Storage.
 **Ranges**: `1h`, `24h`, `7d`, `30d`
 
+### Storage Charts
+`GET /api/storage-charts`
+Returns storage chart data.
+
 ### Storage Stats
 `GET /api/storage/`
 Detailed storage usage per node and pool.
@@ -86,13 +103,29 @@ Combined view of PVE and PBS backups.
 ## 🔔 Notifications
 
 ### Send Test Notification
-`POST /api/notifications/test`
+`POST /api/notifications/test` (admin)
 Triggers a test alert to all configured channels.
 
-### Manage Webhooks
-- `GET /api/notifications/webhooks`
-- `POST /api/notifications/webhooks`
-- `DELETE /api/notifications/webhooks/<id>`
+### Email, Apprise, and Webhooks
+- `GET /api/notifications/email` (admin)
+- `PUT /api/notifications/email` (admin)
+- `GET /api/notifications/apprise` (admin)
+- `PUT /api/notifications/apprise` (admin)
+- `GET /api/notifications/webhooks` (admin)
+- `POST /api/notifications/webhooks` (admin)
+- `PUT /api/notifications/webhooks/<id>` (admin)
+- `DELETE /api/notifications/webhooks/<id>` (admin)
+- `POST /api/notifications/webhooks/test` (admin)
+- `GET /api/notifications/webhook-templates` (admin)
+- `GET /api/notifications/webhook-history` (admin)
+- `GET /api/notifications/email-providers` (admin)
+- `GET /api/notifications/health` (admin)
+
+### Queue and Dead-Letter Tools
+- `GET /api/notifications/queue/stats` (admin)
+- `GET /api/notifications/dlq` (admin)
+- `POST /api/notifications/dlq/retry` (admin)
+- `POST /api/notifications/dlq/delete` (admin)
 
 ---
 
@@ -170,11 +203,13 @@ Streaming variant of execute (used by the UI for incremental responses).
 - `GET /api/ai/patrol/status`
 - `GET /api/ai/patrol/findings`
 - `GET /api/ai/patrol/history`
+- `GET /api/ai/patrol/stream`
 - `POST /api/ai/patrol/run` (admin)
 
 ### Cost Tracking
-`GET /api/ai/cost/summary`
-Get AI usage statistics (includes retention window details).
+- `GET /api/ai/cost/summary`
+- `POST /api/ai/cost/reset` (admin)
+- `GET /api/ai/cost/export` (admin)
 
 ## 📈 Metrics Store (v5)