feat(FN-189): add CHANGELOG_AUTOMATION_TOKEN to env schema (+5 more)

Commits merged:
- docs(FN-189): complete Step 7 — update docs/INDEX.md and MEMORY.md
- fix(FN-189): lint fixes — import order, formatting
- test(FN-189): complete Step 4 — add controller spec with 6 token auth scenarios
- feat(FN-189): complete Step 3 — add Fusion changelog automation trigger to deploy workflow
- feat(FN-189): complete Step 2 — add POST /api/changelog/internal endpoint with token auth
- feat(FN-189): complete Step 1 — add CHANGELOG_AUTOMATION_TOKEN to env schema

Files changed:
.fusion/memory/MEMORY.md                           |  16 +++
 .github/workflows/deploy.yml                       |  17 +++
 .../api/src/changelog/changelog.controller.spec.ts | 122 +++++++++++++++++++++
 apps/api/src/changelog/changelog.controller.ts     |  49 ++++++++-
 docs/INDEX.md                                      |   1 +
 packages/config/src/index.ts                       |   3 +
 6 files changed, 207 insertions(+), 1 deletion(-)

Fusion-Task-Id: FN-189

packages/config/src/index.ts

@@ -76,6 +76,9 @@ export const envSchema = z.object({
 
   // Sentry — error tracking
   SENTRY_DSN: z.string().url().optional(),
+
+  // Changelog automation (token-authed internal endpoint for Fusion webhook)
+  CHANGELOG_AUTOMATION_TOKEN: z.string().min(32).optional(),
 });
 
 export type Env = z.infer<typeof envSchema>;