feat(canvas): complete Pick & polish experience

.github/extensions/replica-prototype/README.md

@@ -16,7 +16,7 @@ After a live action times out, `get_action_diagnostics` reads bounded request an
 
 ## Install
 
-Choose either the current main branch or your organization's approved release. Both use [the same catalog](../../plugin/marketplace.json) and install the plugin with its bundled renderer and publish skill. If the `replica` marketplace is already registered, follow [Update or switch source](#update-or-switch-source) instead of adding it again.
+Choose either the current main branch or your organization's approved release. Both use [the same catalog](../../plugin/marketplace.json) and install the plugin with its bundled renderer, publish skill, and Pick & polish skill. If the `replica` marketplace is already registered, follow [Update or switch source](#update-or-switch-source) instead of adding it again.
 
 To follow the repository's default branch:
 
@@ -68,9 +68,11 @@ Plugin/Hub compatibility uses the supported Canvas interface, not matching relea
 
 Contributors can load uncommitted changes from a local Replica checkout with `copilot --plugin-dir` instead of editing an installed copy. See the [contributor workflow](../../../hub/docs/prototype-canvas.md#contributor-workflow) for local setup and asset build commands.
 
-## Improvement-note persistence
+## Pick & polish
 
-New improvements remain local until their captured source matches a successful published Build, including on branches with an older Build. Clients capture the source without changing the real Git index. Capture failures or missing provenance still allow local use but prevent synchronization. Once uploaded, later changes retain the original Build identity and remain tied to their creator. See the [persistence guide](../../../hub/docs/prototype-canvas.md#improvement-note-persistence) for the runtime API.
+New improvements remain local until their captured source matches a successful published Build, including on branches with an older Build. Target selection captures the source without changing the real Git index. Capture failures or missing provenance still allow local use but prevent synchronization. Once uploaded, later changes retain the original Build identity and remain tied to their creator.
+
+**Fix all** invokes the bundled, model-discoverable [`/replica-pick-and-polish` skill](skills/replica-pick-and-polish/SKILL.md) with the verified checkout, branch, batch ID, and thread count. The agent retrieves all notes and conversation history from that immutable batch in one response. Notes contain saved target metadata, not screenshots. When the skill is missing or disabled, or the runtime has no skill catalog, the request includes the same bundled procedure inline. Catalog or fallback-file errors stop preparation without sending work or leaving a batch awaiting results. See the [Pick & polish guide](../../../hub/docs/prototype-canvas.md#pick--polish) for saved-note and recovery behavior.
 
 ## Learnings