feat: channel audit logging, name cleaning, message formatting, and dashboard UI

- Add audit log entries for channel create, update, rotate_config, delete
- Clean channel names on create/update (trim, lowercase, spaces → hyphens,
  SafeName validation)
- Format chat notifications with full event details (resource, actor, team,
  timestamp) instead of one-liners
- Fix Discord split-line embeds by setting splitLines=No on shoutrrr URL
- Add channels dashboard page and sidebar navigation

frontend/src/lib/api/channels.ts

@@ -0,0 +1,72 @@
+import { apiFetch, type ApiResult } from '$lib/api/client';
+
+export type Channel = {
+	id: string;
+	team_id: string;
+	name: string;
+	provider: string;
+	events: string[];
+	created_at: string;
+	updated_at: string;
+	secret?: string; // only present immediately after creation (webhook provider)
+};
+
+export const PROVIDERS = [
+	{ value: 'discord', label: 'Discord', fields: ['webhook_url'] },
+	{ value: 'slack', label: 'Slack', fields: ['webhook_url'] },
+	{ value: 'teams', label: 'Teams', fields: ['webhook_url'] },
+	{ value: 'googlechat', label: 'Google Chat', fields: ['webhook_url'] },
+	{ value: 'telegram', label: 'Telegram', fields: ['bot_token', 'chat_id'] },
+	{ value: 'matrix', label: 'Matrix', fields: ['homeserver_url', 'access_token', 'room_id'] },
+	{ value: 'webhook', label: 'Webhook', fields: ['url'] }
+] as const;
+
+export const EVENT_TYPES = [
+	{ value: 'capsule.created', group: 'Capsule' },
+	{ value: 'capsule.running', group: 'Capsule' },
+	{ value: 'capsule.paused', group: 'Capsule' },
+	{ value: 'capsule.destroyed', group: 'Capsule' },
+	{ value: 'template.snapshot.created', group: 'Template' },
+	{ value: 'template.snapshot.deleted', group: 'Template' },
+	{ value: 'host.up', group: 'Host' },
+	{ value: 'host.down', group: 'Host' }
+] as const;
+
+export async function listChannels(): Promise<ApiResult<Channel[]>> {
+	return apiFetch('GET', '/api/v1/channels');
+}
+
+export async function createChannel(
+	name: string,
+	provider: string,
+	config: Record<string, string>,
+	events: string[]
+): Promise<ApiResult<Channel>> {
+	return apiFetch('POST', '/api/v1/channels', { name, provider, config, events });
+}
+
+export async function updateChannel(
+	id: string,
+	name: string,
+	events: string[]
+): Promise<ApiResult<Channel>> {
+	return apiFetch('PATCH', `/api/v1/channels/${id}`, { name, events });
+}
+
+export async function deleteChannel(id: string): Promise<ApiResult<void>> {
+	return apiFetch('DELETE', `/api/v1/channels/${id}`);
+}
+
+export async function rotateConfig(
+	id: string,
+	config: Record<string, string>
+): Promise<ApiResult<Channel>> {
+	return apiFetch('PUT', `/api/v1/channels/${id}/config`, { config });
+}
+
+export async function testChannel(
+	provider: string,
+	config: Record<string, string>
+): Promise<ApiResult<{ status: string }>> {
+	return apiFetch('POST', '/api/v1/channels/test', { provider, config });
+}