Task: Merge the org parsers: teach load_org_model() to parse Validation function and Insert trigger sections

A single org model parser handles all entity types; load_org_table_model() is deleted and its callers are removed.

• load_org_model() parses * Validation function body, * Insert trigger / ** Validations list, has_tenant_id, coding_scheme, and image_id from entity org files.
• load_org_table_model() and all call sites are deleted from generator.py.
• All existing table-pathway entities regenerate identical SQL output after the parser merge.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

Done — this is the same work as B3: Teach load_org_model() to parse table-only sections in Resolve codegen model unification blockers, independently re-described here under a different story; no separate implementation needed.