chore: 2.0.0-alpha.9 — security & correctness hardening (Void 3.0 quick wins)

- Q3: prod void DB role NOSUPERUSER (vector marked trusted; deploy/README documents it)
- Q4: buildChildEnv allow-list for the claude subprocess (no OWNER_TOKEN/DATABASE_URL/secrets leak)
- Q5: pending-change approve claims-before-applying + reopens on failure (no re-approvable dup)
- Q6: /capture/upload validates space_id (UUID+existence); pg pool statement_timeout 30s
- Q9: disabled failing syncoid-donatello timer on Z

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/ai/claude_cli_env.test.js

@@ -0,0 +1,36 @@
+import { describe, it, expect } from 'vitest';
+import { buildChildEnv } from '../../lib/ai/claude_cli.js';
+
+describe('buildChildEnv (Q4 — claude child env allow-list)', () => {
+  const parent = {
+    PATH: '/usr/bin', HOME: '/root', LANG: 'C.UTF-8', TERM: 'xterm',
+    CLAUDE_EXE: '/usr/bin/claude', CLAUDE_CONFIG_DIR: '/cfg',
+    OWNER_TOKEN: 'secret-owner', DATABASE_URL: 'postgres://void:pw@db/void',
+    KARAKEEP_API_TOKEN: 'kk', ANTHROPIC_API_KEY: 'sk-ant', ANTHROPIC_AUTH_TOKEN: 'tok',
+    VOID_TOOL_REGISTRY: 'security'
+  };
+
+  it('passes through benign system + CLAUDE_* vars', () => {
+    const env = buildChildEnv(parent);
+    expect(env.PATH).toBe('/usr/bin');
+    expect(env.LANG).toBe('C.UTF-8');
+    expect(env.TERM).toBe('xterm');
+    expect(env.CLAUDE_EXE).toBe('/usr/bin/claude');
+    expect(env.CLAUDE_CONFIG_DIR).toBe('/cfg');
+  });
+
+  it('NEVER leaks app secrets or API keys into the child', () => {
+    const env = buildChildEnv(parent);
+    expect(env.OWNER_TOKEN).toBeUndefined();
+    expect(env.DATABASE_URL).toBeUndefined();
+    expect(env.KARAKEEP_API_TOKEN).toBeUndefined();
+    expect(env.ANTHROPIC_API_KEY).toBeUndefined();
+    expect(env.ANTHROPIC_AUTH_TOKEN).toBeUndefined();
+    expect(env.VOID_TOOL_REGISTRY).toBeUndefined();
+  });
+
+  it('uses the home override for HOME when given', () => {
+    expect(buildChildEnv(parent, '/var/lib/void').HOME).toBe('/var/lib/void');
+    expect(buildChildEnv(parent).HOME).toBe('/root');
+  });
+});