feat(errors): register database suspension error codes

[pyramation]

Summary

Companion to constructive-io/constructive-db#3701 (database access standing). Registers the codes that PR raises so gateways/proxy can map them to canonical public errors:

ACCESS_SUSPENDED          // 403 — "Access to this database is suspended."   (raised by the serving lanes / proxy in PR 1)
SUSPENSION_FORBIDDEN      // 403 — tenant tried to move database.suspended_*  (tg_guard_database_suspension)
SUSPENSION_REASON_INVALID // 400 — reason not in ('billing','admin')          (suspend_database)

ACCESS_SUSPENDED is curated in registry.ts; the other two came in through the normal audit-db-errors.py → generate-registry.py refresh against constructive-db, which also picked up other DB codes added since the last snapshot (MODULE_ENTRY_MALFORMED, CREDENTIAL_NOT_EXTENDABLE, …). Existing FORBIDDEN / NOT_FOUND are reused by the SQL, not duplicated.

Link to Devin session: https://app.devin.ai/sessions/86a73d903b3546c1afbf5361bfa384b6
Open in Devin Desktop: https://app.devin.ai/desktop/session/86a73d903b3546c1afbf5361bfa384b6?variant=devin
Requested by: @pyramation

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment, CI, and merge conflict monitoring

[tenki-reviewer]

Review complete. No blocking issues — approved ✅; 1 nitpick below.

🧹 Nitpicks (1) — 🟢 1 low

• 🟢 ACCESS_SUSPENDED missing from audit snapshot (registry.ts:262) — ACCESS_SUSPENDED is registered in the curated registry (packages/errors/src/registry.ts:262) but is absent from the audit snapshot packages/errors/scripts/db-error-inventory.json and the regenerated packages/errors/src/generated/registry.generated.ts, even though the same commit added the sibling SUSPENSION_FORBIDDEN and SUSPENSION_REASON_INVALID to all three.

---

The change extends packages/errors/src/registry.ts with three curated error codes (ACCESS_SUSPENDED, SUSPENSION_FORBIDDEN, SUSPENSION_REASON_INVALID) carrying optional context fields, and updates packages/errors/scripts/db-error-inventory.json with refreshed counts and new entries.

Files	Change
packages/errors/src/registry.ts	Registers three suspension error codes with optional reason/database_id context and static message templates
packages/errors/scripts/db-error-inventory.json	Refreshes error counts and adds new inventory entries, but omits the new ACCESS_SUSPENDED code

One low-severity consistency gap: ACCESS_SUSPENDED is curated but absent from the audit snapshot and generated registry, unlike its two siblings.

_{Reviewed commit: fe752ed}