[BUG]: TS Direct JSON prompt generator should put the protocol schemas in base rules (TS follow-up to #3526) #3562

The Python fix for #3526 (#3559) moves the Direct JSON protocol schemas (the agent-to-renderer schema and the common types schema) from generate_catalog_instructions() into generate_base_rules(). The TypeScript DirectJsonPromptGenerator needs the same change, so that the two SDKs split their output across the hooks the same way.

Current behavior

typescript/agents/a2ui_agent/src/inference-formats/direct-json/prompt-generator.ts:

• generateBaseRules() returns only DEFAULT_WORKFLOW_RULES.
• generateCatalogInstructions(catalog?) returns the agent-to-renderer schema, the pruned common types schema and the catalog schemas, all in one schema block.

Nothing triggers the duplication on main, because TS has no SkillGenerator yet. Once #3397 lands, SkillGenerator.generateSkill() calls generateCatalogInstructions(c) once per catalog. A monolithic Direct JSON skill with two catalogs would then repeat the protocol schemas, as Python did before #3559.

Expected behavior

Match #3559:

• generateBaseRules(allowedMessages?) returns the workflow rules followed by a schema block with the agent-to-renderer schema (pruned to the allowed messages) and the common types schema (pruned against all of the generator's catalogs).
• generateCatalogInstructions(catalog?) returns a schema block with only the catalog schemas.
• generate() / promptSnippet stays byte-identical, so the prompt conformance fixtures don't change.

Done looks like

• The TS change lands before or together with feat(agent): implement Skill, SkillSet, and SkillGenerator #3397.
• A Direct JSON test with two catalogs checks that the monolithic skill holds the protocol schemas once, the a2ui-core skill holds them, and catalog skills don't.
• Once both SDKs agree, a Direct JSON case can be added to conformance/agent/skill.yaml ([v1.0][skill] Heading mismatch (### Examples: vs ## Examples) in SkillGenerator and zero direct_json test cases in conformance/agent/skill.yaml #3464).

Related: #3416, #3526, #3559, #3397.