feat: add constructive-platform-seed (compute API + domain + site metadata)

[pyramation]

Summary

Adds pgpm/constructive-platform-seed — an idempotent seed package that registers the platform metadata required for API resolution, mirroring how constructive-db's provisioning system attaches apis/domains/sites in production without RLS.

The seed creates the full routing chain the server needs to resolve a request into schemas:

services_public.domains ('compute.localhost')
  → services_public.apis ('compute', authenticated/anonymous, public)
    → services_public.api_schemas (5 links)
      → metaschema_public.schema (infra, store, objects, fbp, storage)
        → metaschema_public.database (well-known 00000000-…-000000000000)

All inserts use ON CONFLICT DO NOTHING for idempotency. The compute API exposes all 5 module public schemas (constructive_infra_public, _store_public, _objects_public, _fbp_public, _storage_public).

scripts/up.sh deployment order updated:

Step 4: modules (infra, store, objects, fbp, storage)
Step 5: constructive-platform-seed  ← NEW (creates database row + metadata)
Step 6: constructive-infra-services ← NEW (registers function_module, needs DB row)
Step 7: constructive-infra-seed     (seeds namespaces + function definitions)

The package declares requires = 'metaschema-schema,services' — pgpm resolves these from the vendored extensions/@pgpm/ packages (no new external deps).

Link to Devin session: https://app.devin.ai/sessions/633efc205f0c445dbbb61c40679c2f78
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