refactor(spec): restructure v0.9 and v0.10 catalog files into dedicat…

[gspencergoog]

Restructure v0.9 and v0.10 catalogs into dedicated modular directories

This change restructures the basic and minimal component and function catalogs for both v0.9 and v0.10 specifications, moving them out of /json/ and into a dedicated /catalogs/ folder under each version root. Cross-schema references are transitioned to absolute canonical URIs to prevent repository directory structure leakage into the public specification.

Proposed directory reorganization

specification/
├── v0_10/
│   ├── catalogs/
│   │   ├── basic/
│   │   │   ├── catalog.json            # (formerly basic_catalog.json)
│   │   │   ├── rules.txt               # (formerly basic_catalog_rules.txt)
│   │   │   └── examples/               # basic catalog JSON examples
│   │   └── minimal/
│   │       ├── catalog.json            # (formerly minimal_catalog.json)
│   │       └── examples/               # minimal catalog JSON examples
│   └── json/                           # Core protocol schemas

Key design decisions

• Canonical absolute URIs: Relative paths (like ../../json/common_types.json) were replaced with canonical absolute URIs (e.g., https://a2ui.org/specification/v0_10/common_types.json) to completely decouple the schemas from the repository directory layout.
• Interface binding: Kept relative "catalog.json" references inside core schemas, allowing Ajv to bind references natively in memory against whichever catalog is registered.

PR breakdown

• Specification & Tooling: Modularized v0.9 & v0.10 basic/minimal catalogs and examples, updated specification/scripts/validate.py to validate v0.10 natively, and updated assemble_catalog.py basic catalog URLs.
• Renderers & Packaging:
  • Updated copy-spec.js to copy the modular catalogs/ directory during package builds for versions >= v0.9, while completely skipping it for v0.8.
  • Ignored generated src/v0_10/schemas/ build products in .gitignore and untracked them from Git.
  • Updated Lit, Angular, and React adapters, demo catalogs, and test suites to match the new catalog IDs and directories.
• Python SDK & Evals: Updated constants paths, revised the common types pruning utility in catalog.py to handle absolute canonical URIs, and refactored prompt/scorer tasks under eval/ to resolve new paths.
• Composer Tool: Fixed the examples syncing script to look in the sibling directories, resolved missing test dependencies by adding @testing-library/dom, and updated pnpm-lock.yaml.

Testing and verification

All packages, tests, and build pipelines are passing:

• python3 specification/scripts/validate.py (All 36 schema examples validated)
• test_assemble_catalog.py (All 18 unit tests passed)
• uv run pytest in agent_sdks/python (All 245 tests passed)
• uv run python3 -m pytest in eval/ (All 21 evaluation tests passed)
• npm run test in renderers/react (All 446 tests passed)
• pnpm test in tools/composer (All 32 tests passed)
• Successfully compiled @a2ui/web_core and successfully built MkDocs site.

Fixes #865

[josemontespg]

Nice improvement, thank you!