chore: version 2.0.0-alpha.2 + changelog

Search view: read ?q from hash, call /api/search, group hits by kind
with rank + space_id; sidebar filters for kinds and space_id; updates
on Enter or filter change.

Bumps package.json + server.js VERSION to 2.0.0-alpha.2 and pins the
/health version assertion to match.

CHANGELOG: full Plan 2 entry covering API surface, capability tiering,
audit chain extension (approve/reject events), and the SPA shell.

Security: adds safeHref() to dom.js and applies it everywhere an
API-supplied URL becomes href / src (reference media block + reference
source_url anchor + resource url anchor). javascript: and other
non-http(s)/mailto schemes from agent-suggested content can no longer
execute in the owner's browser.

Plan 2 surface is feature-complete: 22/22 tasks landed, 185 tests
across 43 files, SPA renders end-to-end including the suggest -> approve
agent flow.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

server.js

@@ -4,7 +4,7 @@ import { pool } from './lib/db/pool.js';
 import { log } from './lib/log.js';
 import { mountApi } from './lib/api/index.js';
 
-const VERSION = '2.0.0-alpha.1';
+const VERSION = '2.0.0-alpha.2';
 
 export function createApp() {
   const app = express();