Add AgentAd ad schemas as a LogicSRC primitive (#10)

* Add AgentAd ad schemas as a LogicSRC primitive

AgentAd is a disclosed, agent-readable advertising contract for CLI tools
and AI agents. LogicSRC owns the canonical schemas; cl1s.tech is the
reference network built on them.

- packages/schemas: agentad-{ad,placement,ad-request,ad-response,
  impression,click,campaign} schemas (id under schemas.logicsrc.com) +
  ad/placement fixtures, exported from @logicsrc/schemas
- packages/validators: register the 7 agentad kinds, wire fixture
  validation, add tests (disclosure.sponsored must be true)
- docs/agentad.md: the AgentAd spec
- README: list AgentAd under v1 priorities

Validators build clean; all fixtures validate; vitest 4/4 green.

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

* Prepare @logicsrc/schemas for npm publish

Add license, repository, homepage, keywords, publishConfig (public),
and a package README covering both the logicsrc-* core schemas and the
agentad-* family.

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

---------

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

packages/validators/package.json

@@ -11,7 +11,7 @@
   "scripts": {
     "build": "tsc -p tsconfig.json",
     "test": "vitest run src",
-    "validate:fixtures": "node dist/cli.js task ../schemas/fixtures/task.yaml && node dist/cli.js agent ../schemas/fixtures/agent.yaml"
+    "validate:fixtures": "node dist/cli.js task ../schemas/fixtures/task.yaml && node dist/cli.js agent ../schemas/fixtures/agent.yaml && node dist/cli.js agentad-ad ../schemas/fixtures/agentad-ad.yaml && node dist/cli.js agentad-placement ../schemas/fixtures/agentad-placement.yaml"
   },
   "dependencies": {
     "ajv": "^8.17.1",