feat: v0.2 — template-driven real handlers in generateRoutes()

[stackbilt-admin]

Problem

generateRoutes() currently emits stub handlers:

lines.push(`  // TODO: implement ${routeName} handler`);
lines.push(`  return c.json({ status: 'ok' });`);

Specs pass but handlers are hollow. No DB queries, no response shaping, no error handling. This blocks FoodFiles domain contracts (Stackbilt-dev/foodfilesapi_v2#23) from producing usable code.

Decided Approach: Handlebars-style string templates

Per prior architecture decision:

1. Template files under src/generators/templates/ with placeholders ({{contractName}}, {{inputSchema}}, {{refImports}}, etc.)
2. Zod walker builds a context object, feeds it to templates
3. Generated handler bodies include:
   • req.body validation against Zod schema (already done)
   • DB queries via surfaces.db helpers (db.prepare().bind().run() for D1)
   • Standard success/error response shaping (try/catch with errorResponse() envelope)
   • State transition guards from contract.states
   • Authority middleware from contract.authority (already done)
4. Prettier pass on output

Why Templates (Not AST)

• Speed: instant iteration on contract definitions
• Auditability: deterministic, diffable output
• Low risk: no complex AST transforms — aligns with speed + rigor

AST-based generation (ts-morph) is v0.3, gated on template coverage ≥ 90%.

Scope

Must have (v0.2)

• Route template: CRUD handler bodies (create, read, update, delete, list)
• Route template: state transition operations (e.g., publish, archive)
• DB query generation from surfaces.db.table + schema columns
• ref() → JOIN clause generation
• Error handling: try/catch with structured error response
• Test harness: generated code compiles, zero TODO markers

Also fix

• generateSQL() — validate against FoodFiles migration 001 (recipe/org tables)
• generateSDK() — fix syntax bug (unmatched paren line 72)
• generateTests() — emit integration tests that hit handlers, not just schema validation

Validation Target

Write RecipeContract (state machine: draft→published→archived, refs to Organization + User, invariant: published requires ingredients). Run all generators. Diff SQL against FoodFiles 001_fresh_multitenant_schema.sql.

Roadmap

Version	Approach	Status
v0.1	Stub handlers	Done
v0.2	Template-driven real handlers	This issue
v0.3	AST-based generation (ts-morph)	Planned
v0.4	CI integration + no-TODO lint rule	Planned