workspace: add rich console rendering

.yoi/tickets/00001KX72G8Z6/item.md

@@ -1,8 +1,8 @@
 ---
 title: 'Add rich markdown tool rendering to workspace console'
-state: 'inprogress'
+state: 'done'
 created_at: '2026-07-10T22:31:21Z'
-updated_at: '2026-07-10T22:31:41Z'
+updated_at: '2026-07-10T22:45:55Z'
 assignee: null
 queued_by: 'yoi ticket'
 queued_at: '2026-07-10T22:31:41Z'

.yoi/tickets/00001KX72G8Z6/thread.md

@@ -39,4 +39,35 @@ Ticket を `yoi ticket` が queued にしました。
 State changed to `inprogress`.
 
 
+---
+
+<!-- event: implementation_report author: hare at: 2026-07-10T22:45:55Z -->
+
+## Implementation report
+
+Implemented rich Workspace Console rendering.
+
+- Added safe Markdown-to-HTML rendering for console bodies; raw HTML is escaped.
+- Added Shiki highlighting for fenced code blocks.
+- Added TUI-inspired Console colors for message kinds, tool types, tool states, and diff rows.
+- Added structured Edit diff projection using old_string/new_string and rendered add/remove/context rows.
+- Kept Read aggregate behavior: consecutive Read calls are grouped and file content is not shown in the body.
+- Added tests for Markdown escaping/Shiki rendering and Edit diff projection.
+
+Validation:
+- cd web/workspace && deno task check
+- cd web/workspace && deno task test
+- git diff --check
+- nix build .#yoi --no-link
+
+
+---
+
+<!-- event: state_changed author: "yoi ticket" at: 2026-07-10T22:45:55Z from: inprogress to: done reason: cli_state field: state -->
+
+## State changed
+
+State changed to `done`.
+
+
 ---