feat(spec): create seeds for agent / tool / skill / email_template / permission (#2282)

Extends the spec-derived create-shape contract to the AI + integration metadata
types. Each gets an authoritative minimal create seed (empirically derived from
its schema's required fields, validated by metadata-create-seeds.test.ts):
agent (role+instructions), tool (description+parameters), skill (tools),
email_template (subject+bodyHtml), permission (objects). They flow to the
designer/CLI/API via /meta/types (no further wiring needed). `trigger` has no
spec schema and stays unseeded.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: os-zhuang

.changeset/ai-type-create-seeds.md

@@ -0,0 +1,7 @@
+---
+'@objectstack/spec': minor
+---
+
+Add authoritative create seeds for agent / tool / skill / email_template / permission
+
+Extends the spec-derived create-shape contract to the AI and integration metadata types. Each now has an authoritative minimal create seed (validated against its schema), so the Studio designer / CLI / API derive their create defaults from the spec via `/meta/types` — closing the "designer emits a minimal shape the spec rejects → create→save 422" gap for these types too (agent needs `role`+`instructions`, tool needs `description`+`parameters`, skill needs `tools`, email_template needs `subject`+`bodyHtml`, permission needs `objects`). `trigger` has no spec schema and is intentionally not seeded.

packages/spec/src/kernel/metadata-create-seeds.ts

@@ -104,6 +104,38 @@ const BUILTIN_METADATA_CREATE_SEEDS: Partial<Record<MetadataType, unknown>> = {
     pluralLabel: 'New Objects',
     fields: {},
   },
+  agent: {
+    name: 'new_agent',
+    label: 'New Agent',
+    // role + instructions are required — the agent's persona and behavior.
+    role: 'A helpful assistant.',
+    instructions: 'Describe what this agent should do.',
+  },
+  tool: {
+    name: 'new_tool',
+    label: 'New Tool',
+    // description + a (possibly empty) parameters record are required.
+    description: 'Describe what this tool does.',
+    parameters: {},
+  },
+  skill: {
+    name: 'new_skill',
+    label: 'New Skill',
+    // a skill bundles tools; an empty list is a valid starting point.
+    tools: [],
+  },
+  email_template: {
+    name: 'new_email_template',
+    label: 'New Email Template',
+    subject: 'Subject line',
+    bodyHtml: '<p>Email body</p>',
+  },
+  permission: {
+    name: 'new_permission',
+    label: 'New Permission',
+    // a permission set's per-object grant map; empty = no grants yet.
+    objects: {},
+  },
 };
 
 /**