MVP tracker: Format-first Events Roundup carousel builder

[breadback00-dev]

What is the work

Track the full MVP implementation for the format-first Events Roundup carousel builder from the plan in docs/plans/2026-05-07-001-feature-format-first-carousel-builder-plan.md.

This tracker groups the implementation-unit issues and makes the dependency structure explicit.

Why does it matter

The plan has several dependent layers: app scaffold, Convex domain model, format definition, intake, image handling, source review, SVG rendering, Sharp export, documentation, and end-to-end acceptance coverage. Without a dependency map, parallel work could create merge conflicts or build features on unstable foundations.

Issue set

• U1: Scaffold Next.js, Convex, and test harness #1
• U2: Define core Convex domain model #2
• U3: Seed product-managed Events Roundup format #3
• U4: Build agent intake guidance and parser adapter #4
• U5: Add image upload and source URL handling #5
• U6: Build source review workspace #6
• U7: Build SVG template renderer and text-fit signals #7
• U8: Add Sharp export pipeline #8
• U9: Document agent and editorial safety guidance #9
• U10: Add end-to-end acceptance coverage #10

Dependency graph

flowchart TD
  U1["#1 U1 Scaffold app/test harness"] --> U2["#2 U2 Core Convex domain model"]
  U1 --> U3["#3 U3 Events Roundup format"]
  U2 --> U3
  U2 --> U4["#4 U4 Agent intake guidance/parser"]
  U3 --> U4
  U2 --> U5["#5 U5 Image upload/source URLs"]
  U4 --> U5
  U4 --> U6["#6 U6 Source review workspace"]
  U5 --> U6
  U3 --> U7["#7 U7 SVG renderer/text-fit"]
  U6 --> U7
  U7 --> U8["#8 U8 Sharp export pipeline"]
  U4 --> U9["#9 U9 Agent/editorial guidance docs"]
  U1 --> U10["#10 U10 E2E acceptance coverage"]
  U2 --> U10
  U3 --> U10
  U4 --> U10
  U5 --> U10
  U6 --> U10
  U7 --> U10
  U8 --> U10

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Suggested sequencing

1. Start with U1: Scaffold Next.js, Convex, and test harness #1.
2. Then do U2: Define core Convex domain model #2.
3. Then U3: Seed product-managed Events Roundup format #3 and early U9: Document agent and editorial safety guidance #9 can proceed, with U9: Document agent and editorial safety guidance #9 staying careful not to depend on unimplemented UI details.
4. After U3: Seed product-managed Events Roundup format #3, do U4: Build agent intake guidance and parser adapter #4.
5. After U4: Build agent intake guidance and parser adapter #4, U5: Add image upload and source URL handling #5 and U9: Document agent and editorial safety guidance #9 can run in parallel.
6. After U5: Add image upload and source URL handling #5, do U6: Build source review workspace #6.
7. After U6: Build source review workspace #6, do U7: Build SVG template renderer and text-fit signals #7.
8. After U7: Build SVG template renderer and text-fit signals #7, do U8: Add Sharp export pipeline #8.
9. Finish with U10: Add end-to-end acceptance coverage #10 as the cross-flow acceptance pass.

Parallel worktree opportunities

• After U1: Scaffold Next.js, Convex, and test harness #1 and U2: Define core Convex domain model #2: split U3: Seed product-managed Events Roundup format #3 (format metadata/UI entry) and U4: Build agent intake guidance and parser adapter #4 (intake adapter/guidance fixtures) only if interfaces between format metadata and intake targets are agreed first.
• After U4: Build agent intake guidance and parser adapter #4: split U5: Add image upload and source URL handling #5 (image assets) and U9: Document agent and editorial safety guidance #9 (agent/editorial guidance docs). These have mostly separate write sets.
• After U5: Add image upload and source URL handling #5: U6: Build source review workspace #6 should probably be one focused branch because it touches review UI and source-item state together.
• After U6: Build source review workspace #6: U7: Build SVG template renderer and text-fit signals #7 and U8: Add Sharp export pipeline #8 should not be parallelized unless U7: Build SVG template renderer and text-fit signals #7 first lands a stable SVG render contract. U8: Add Sharp export pipeline #8 depends heavily on canonical SVG output.
• U10: Add end-to-end acceptance coverage #10 should be last: it is integration-heavy and will churn if started too early, though fixtures can be sketched earlier in a separate branch.

What does done mean

• Issues U1: Scaffold Next.js, Convex, and test harness #1 through U10: Add end-to-end acceptance coverage #10 are closed.
• The app supports the end-to-end Events Roundup workflow from format selection through intake, review, SVG preview, and Sharp export.
• Verification from U10: Add end-to-end acceptance coverage #10 passes across Playwright, Vitest, Convex tests, and Sharp render/export tests.

Acceptance criteria

• Every implementation unit issue has been completed or deliberately rescheduled.
• Dependency blockers in child issues have been respected or updated with rationale.
• End-to-end acceptance coverage proves the MVP workflow.
• README and docs reflect the actual implementation.

Blockers

• Blocked by the completion of U1: Scaffold Next.js, Convex, and test harness #1 through U10: Add end-to-end acceptance coverage #10.

What can make this fail

• Work starts on SVG export before the canonical SVG renderer contract exists.
• Parallel worktrees modify the same schema/components without a stable boundary.
• Agent intake behavior is tested only with live model calls instead of deterministic fixtures.
• Export succeeds locally but fails in the deployment runtime.

How should Codex verify it

• Track issue closure and PR links for U1: Scaffold Next.js, Convex, and test harness #1 through U10: Add end-to-end acceptance coverage #10.
• Run the full test suite after integrating the final issue.
• Manually exercise the full Events Roundup flow in the browser.
• Verify exported PNG/JPG assets have expected dimensions and slide count.
• Confirm GitHub issues and docs still match the implemented behavior.