<!-- Use a conventional commit-style title, such as "fix(hub): retain
prototype history". -->

## Why

<!-- Explain the problem and why this change matters in a short,
plain-English paragraph. Link the issue when applicable. -->

The prototype canvas needs a stable Hub account ID for the connected
viewer. The connection response currently provides only their login,
even though Hub already knows the authenticated account.

## What changes

<!-- Describe what becomes different for a first-time reader. Explain
necessary terms. Include accurate Mermaid diagrams when they clarify the
proposal, using before/after diagrams when helpful. Add screenshots for
meaningful UI changes. -->
<!-- Omit validation sections, checklists, and routine test/CI summaries
such as "CI is green" or "tests passed". Mention only known verification
gaps that affect the change, not disclaimers about drafting this
description. -->

Authenticated `GET /api/canvas/connection` responses now include
`viewerId`, the current user's internal Hub ID. Existing login and
repository authorization behavior remain unchanged, and the response
works before any prototype exists.

This is an independent extraction from #13. It adds no Pick & polish
functionality and needs only a Hub deployment to expose the new field.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 9e593c03-e358-4cd6-9fc0-ac3d917635d2

<!-- Use a conventional commit-style title, such as "fix(hub): retain
prototype history". -->

## Why

<!-- Explain the problem and why this change matters in a short,
plain-English paragraph. Link the issue when applicable. -->

Prototype authors need to retain Pick & polish requests and Copilot
answers without turning private improvement work into team review
conversations. This is the server foundation of the Pick & polish stack,
extracted from #13; local synchronization and the canvas interface
follow separately.

## What changes

<!-- Describe what becomes different for a first-time reader. Explain
necessary terms. Include accurate Mermaid diagrams when they clarify the
proposal, using before/after diagrams when helpful. Add screenshots for
meaningful UI changes. -->
<!-- Omit validation sections, checklists, and routine test/CI summaries
such as "CI is green" or "tests passed". Mention only known verification
gaps that affect the change, not disclaimers about drafting this
description. -->

Hub stores each request or agent response in a separate
`ImprovementComment` row, not in `ReviewComment`. Foreign keys connect
replies to their original request, and `ImprovementCommentReply` links
an agent response to the requests it answers. The API returns one
current `thread` shape, assembled from these records rather than stored
as a JSON conversation or lists of IDs. Synchronization validates and
saves the conversation in one transaction.

Initial uploads require a successful Build. Unpublished notes remain on
the author's device until the client verifies that their captured source
was published; later changes retain the original Build. The paired API
checks repository access, saves only the authenticated creator's notes,
and rejects stale or conflicting revisions. Notes remain outside
ordinary review interfaces, summaries, unread state, notifications,
analytics and learning. Paired comment lists must explicitly request
them.

Conversations preserve the original request, follow-ups, answers and
immutable owner snapshots without legacy conversions, version
negotiation or speculative collection limits. Creator and raw comment
feeds return complete collections; existing browser and agent readers
use that contract. Compact agent output retains its separate pagination.
Deletion clears message text and author snapshots while retaining
tombstones. The unshipped relational migration and API guide are updated
together; development databases that ran an earlier copy need a fresh
database or a deliberate rollback and reapply after preserving needed
data. Local synchronization and the canvas interface remain in #41 and
#42.

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b55e539f-c9ba-4320-b39f-bf94f18c0f33

<!-- Use a conventional commit-style title, such as "fix(hub): retain
prototype history". -->

## Why

<!-- Explain the problem and why this change matters in a short,
plain-English paragraph. Link the issue when applicable. -->

Pick & polish needs to retain authors' requests across canvas reloads
and pass only explicitly selected work to Copilot. This is the second
extraction from #13, built on the Hub persistence contracts in #39.

## What changes

<!-- Describe what becomes different for a first-time reader. Explain
necessary terms. Include accurate Mermaid diagrams when they clarify the
proposal, using before/after diagrams when helpful. Add screenshots for
meaningful UI changes. -->
<!-- Omit validation sections, checklists, and routine test/CI summaries
such as "CI is green" or "tests passed". Mention only known verification
gaps that affect the change, not disclaimers about drafting this
description. -->

The extension stores notes in private local files, preserves
conversation history and saved author identity, and synchronizes
revisions with Hub without registering or publishing a prototype.
Guarded HTTP and canvas actions reject stale checkout, account and note
state. Shared identity validators accept Enterprise Managed User logins
containing underscores. Notes without saved author snapshots remain
unattributed rather than being claimed automatically.

Clients capture the local source before selecting a target. New notes
stay local until a successful published Build matches that exact source
and was published after the note was saved. Capture failures and older
notes without provenance remain usable locally, with an explicit
synchronization limitation. The client saves the chosen Build before its
first upload, so an uncertain result or restart cannot bind another
Build; follow-ups, status changes and deletion retain it.

Explicit fix requests save immutable batches before handing work to
Copilot. Results update only captured requests still awaiting answers
and return a small acknowledgment; later follow-ups remain separate
work. Synchronization and batch retrieval read complete collections.
Local storage and Hub use one current conversation shape without legacy
conversion, version negotiation, screenshots or speculative collection
and history limits. The anchor validator is generated from readable Hub
source and minified with the existing Vite pipeline used by the preview
bridge and Controls validator. Renderer, selection bridge and visible UI
changes remain in #42; this PR does not enable a new canvas interface.

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b55e539f-c9ba-4320-b39f-bf94f18c0f33
Copilot-Session: 9f678139-aaa7-4c9a-90a4-2f091027b85c

<!-- Use a conventional commit-style title, such as "fix(hub): retain
prototype history". -->

## Why

<!-- Explain the problem and why this change matters in a short,
plain-English paragraph. Link the issue when applicable. -->

Prototype authors need to select improvements in the live preview and
discuss follow-ups without losing earlier requests or Copilot answers.
This is the final UI layer over #41, extracted from #13 without changing
its backend or local-storage contracts.

## What changes

<!-- Describe what becomes different for a first-time reader. Explain
necessary terms. Include accurate Mermaid diagrams when they clarify the
proposal, using before/after diagrams when helpful. Add screenshots for
meaningful UI changes. -->
<!-- Omit validation sections, checklists, and routine test/CI summaries
such as "CI is green" or "tests passed". Mention only known verification
gaps that affect the change, not disclaimers about drafting this
description. -->

Pick & polish adds element and region selection, saved pins,
conversations, human follow-ups, and explicit Fix all requests. Pins and
conversations render the complete collection without silent truncation
or legacy conversion. Shared conversation components preserve ordinary
review metadata and actions. The accepted toolbar, Controls help link,
avatars, and draft protections are included with regenerated extension
assets and the complete guide.

Starting target selection captures the source through #41's runtime API.
Saving never replaces that capture. New improvements stay local until a
matching successful Build is published; later follow-ups and deletion
retain the same Build.

Fix all uses the bundled, discoverable `/replica-pick-and-polish` skill.
Its request contains checkout and batch metadata; the skill retrieves
all captured notes and conversation history in one response. Notes
retain target metadata, not screenshots. Sessions without an available
skill use the same bundled procedure inline. Preparation errors stop
dispatch without leaving a pending batch.

The standalone Storybook prototype app is removed. Small fixtures use
the real conversation component rather than recreating selection,
storage and agent behavior. The packaged-renderer check covers one
functional flow instead of asserting colors, spacing or pixels. Human
visual review uses the screenshots below.

The retained live conversation and sidebar, captured through the
packaged renderer with a local fixture preview and simulated agent
answers:

![Pick and polish with the saved request, follow-up and two Copilot
answers](https://github.com/user-attachments/assets/4d180b40-8204-4881-b9b5-323e5a6c5ac5)

![Disabled Fix all counter inherits the light-theme label
color](https://github.com/user-attachments/assets/2a2cf769-31d1-49f7-82f4-908064817823)

![Disabled Fix all counter inherits the dark-theme label
color](https://github.com/user-attachments/assets/6d96cac9-f586-4ba2-a122-71e1e0f05498)

![Inset error messages in the Improvement sidebar, conversation, and
deletion
dialog](https://github.com/user-attachments/assets/0ad65037-064b-4d3d-998c-2ac0d03e91e1)

These screenshots use the packaged renderer in an isolated fixture. The
independent connection identity change in #40 remains outside this
stack; unavailable immutable viewer identity is reported as an
attribution error. Formal accessibility review remains deferred as
requested. Native-host rendering and deployed authenticated Build
behavior are not established by the isolated fixture checks.

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b55e539f-c9ba-4320-b39f-bf94f18c0f33
Copilot-Session: 9f678139-aaa7-4c9a-90a4-2f091027b85c
Copilot-Session: 96b94d6f-ee24-4ed6-861e-c1005213ed83
Copilot-Session: 03c141fe-2f30-4317-81df-1051bac1d3ab