bug: AI-generated calendar sections are unusable — buildTemplateDoc omits calendarCategories

Description

The section-generation prompt allows viewType: "calendar" (src/lib/profile/generate-sections.ts:39) and parseSections passes it through, but buildTemplateDoc (src/lib/profile/persist-sections.ts:34-63) never populates calendarCategories. The model default is undefined (section-template.ts:85). Entry creation enforces validateCalendarEvent(body, template.calendarCategories ?? []) (src/app/api/sections/[slug]/entries/route.ts:117-121 → validations.ts:309), and with an empty category array categories.some(...) is always false.

Failure scenario

The adaptive engine generates a calendar-view section. The user opens it and adds any event → POST always returns 400 "Unknown category". The section can never hold a single entry. (The manual template POST path defaults to DEFAULT_CATEGORIES — templates/route.ts:72-77 — so only the adaptive-engine path is broken.)

Fix

In buildTemplateDoc, default calendarCategories to DEFAULT_CATEGORIES when viewType === "calendar" (or have the generator emit categories).

Severity

Medium (feature entirely unusable when generated).

Start in src/lib/profile/persist-sections.ts at buildTemplateDoc, then compare its calendar handling with DEFAULT_CATEGORIES in src/app/api/templates/route.ts and validation in src/lib/profile/validations.ts. Reproduce an adaptive-generated calendar section and verify that posting an event no longer returns 400 "Unknown category" when the section has no model-supplied categories.