feat(defects): read API — feed, per-section counts and history (T6)

GET /api/defects returns a newest-first feed joined to the project name,
bounded by limit; ?section=ID narrows to one section's history. GET
/api/defects/counts returns { sectionId: n } for the weak-point map. Adds a
(section_id, created_at) index and a db:seed script; ~2k rows query in ~20ms.

tests/defects-read.spec.ts

@@ -0,0 +1,58 @@
+import { describe, it, expect, beforeAll, beforeEach, afterAll } from 'vitest'
+import { setupTestDb, truncateAll, type TestDb } from './helpers/db'
+import { createProject } from '../server/db/repositories/projects'
+import { listDefects, countDefectsBySection } from '../server/db/repositories/defects'
+import { defects } from '../server/db/schema'
+
+let db: TestDb
+let pool: { end: () => Promise<void> }
+
+beforeAll(async () => {
+  const setup = await setupTestDb()
+  db = setup.db
+  pool = setup.pool
+})
+
+afterAll(async () => {
+  await pool.end()
+})
+
+// Three defects across two sections with controlled timestamps:
+//   macroplan: "old" (Jan 1), "new" (Feb 1)
+//   feature-kanban: "kanban" (Jan 15)
+beforeEach(async () => {
+  await truncateAll(db)
+  const project = await createProject(db, 'Acme')
+  await db.insert(defects).values([
+    { sectionId: 'macroplan', projectId: project.id, verbatim: 'old', reporterEmail: 'a@theodo.com', createdAt: new Date('2026-01-01T00:00:00Z') },
+    { sectionId: 'macroplan', projectId: project.id, verbatim: 'new', reporterEmail: 'a@theodo.com', createdAt: new Date('2026-02-01T00:00:00Z') },
+    { sectionId: 'feature-kanban', projectId: project.id, verbatim: 'kanban', reporterEmail: 'a@theodo.com', createdAt: new Date('2026-01-15T00:00:00Z') },
+  ])
+})
+
+describe('listDefects', () => {
+  it('returns the feed newest-first with the project name', async () => {
+    const feed = await listDefects(db)
+    expect(feed.map((d) => d.verbatim)).toEqual(['new', 'kanban', 'old'])
+    expect(feed[0]!.projectName).toBe('Acme')
+  })
+
+  it('filters to a single section when given one', async () => {
+    const feed = await listDefects(db, { sectionId: 'macroplan' })
+    expect(feed.map((d) => d.verbatim)).toEqual(['new', 'old'])
+  })
+
+  it('bounds the feed to the requested limit', async () => {
+    const feed = await listDefects(db, { limit: 1 })
+    expect(feed.map((d) => d.verbatim)).toEqual(['new'])
+  })
+})
+
+describe('countDefectsBySection', () => {
+  it('returns a per-section count map', async () => {
+    expect(await countDefectsBySection(db)).toEqual({
+      macroplan: 2,
+      'feature-kanban': 1,
+    })
+  })
+})