diff --git a/.yoi/tickets/20260608-110940-001/item.md b/.yoi/tickets/20260608-110940-001/item.md
index 1af264e1..10a064af 100644
--- a/.yoi/tickets/20260608-110940-001/item.md
+++ b/.yoi/tickets/20260608-110940-001/item.md
@@ -1,8 +1,8 @@
 ---
 title: "Simplify Ticket identity to timestamp key and title"
-state: "inprogress"
+state: 'closed'
 created_at: "2026-06-08T11:09:40Z"
-updated_at: "2026-06-09T05:04:45Z"
+updated_at: '2026-06-09T05:41:12Z'
 queued_by: "workspace-panel"
 queued_at: "2026-06-09T02:13:30Z"
 ---
diff --git a/.yoi/tickets/20260608-110940-001/resolution.md b/.yoi/tickets/20260608-110940-001/resolution.md
new file mode 100644
index 00000000..8a8ea38e
--- /dev/null
+++ b/.yoi/tickets/20260608-110940-001/resolution.md
@@ -0,0 +1,25 @@
+Implemented, reviewed, merged, and validated.
+
+Summary:
+- Migrated current Ticket storage from `.yoi/tickets/{open,pending,closed}/<id-or-slug>/` buckets to flat `.yoi/tickets/<ticket-id>/` directories.
+- Simplified current Ticket identity to opaque path-derived canonical IDs such as `YYYYMMDD-HHMMSS-NNN`; title remains user-facing display/search text, but slug/title words are not canonical identity.
+- Simplified current frontmatter to use canonical `state` instead of independent `status` / `workflow_state` axes.
+- Removed current authority for frontmatter `id`, `slug`, `kind`, unmanaged `labels`, `status`, and `workflow_state`.
+- Preserved distinct `done` vs `closed` lifecycle semantics; close records `state: closed` and `resolution.md` without moving directories.
+- Updated Ticket backend, CLI, built-in tools, panel/TUI, role/session claims, orchestration-plan references, workflows, docs, tests, and local Ticket records to the flat ID/state model.
+- Migrated local Ticket records, including merge-boundary records created while the branch was under review.
+
+Implementation:
+- Coder commits included `191a875`, `591db3f`, `21114fd`, `8fe4b82`, `6ca27f3`, and `a6326a9`.
+- Reviewer approved after fix loops.
+- Merge commit: `634da5d merge: simplify ticket identity fields`.
+
+Validation:
+- Pre-merge and merge-boundary validation passed:
+  - `cargo fmt --check`
+  - `git diff --check`
+  - `cargo run -q -p yoi -- ticket doctor`
+  - `cargo test -p ticket`
+  - `cargo check --workspace`
+  - `nix build .#yoi`
+- After runtime/tooling refresh, new tools also read the flat layout successfully and `cargo run -q -p yoi -- ticket doctor` reports `doctor: ok`.
diff --git a/.yoi/tickets/20260608-110940-001/thread.md b/.yoi/tickets/20260608-110940-001/thread.md
index 535e6b62..3de419b0 100644
--- a/.yoi/tickets/20260608-110940-001/thread.md
+++ b/.yoi/tickets/20260608-110940-001/thread.md
@@ -686,4 +686,46 @@ Validation passed from the worktree:
 
 Worktree remained clean after review.
 
+---
+
+<!-- event: state_changed author: hare at: 2026-06-09T05:41:12Z from: inprogress to: closed reason: closed field: state -->
+
+## State changed
+
+Ticket を closed にしました。
+
+
+---
+
+<!-- event: close author: hare at: 2026-06-09T05:41:12Z status: closed -->
+
+## 完了
+
+Implemented, reviewed, merged, and validated.
+
+Summary:
+- Migrated current Ticket storage from `.yoi/tickets/{open,pending,closed}/<id-or-slug>/` buckets to flat `.yoi/tickets/<ticket-id>/` directories.
+- Simplified current Ticket identity to opaque path-derived canonical IDs such as `YYYYMMDD-HHMMSS-NNN`; title remains user-facing display/search text, but slug/title words are not canonical identity.
+- Simplified current frontmatter to use canonical `state` instead of independent `status` / `workflow_state` axes.
+- Removed current authority for frontmatter `id`, `slug`, `kind`, unmanaged `labels`, `status`, and `workflow_state`.
+- Preserved distinct `done` vs `closed` lifecycle semantics; close records `state: closed` and `resolution.md` without moving directories.
+- Updated Ticket backend, CLI, built-in tools, panel/TUI, role/session claims, orchestration-plan references, workflows, docs, tests, and local Ticket records to the flat ID/state model.
+- Migrated local Ticket records, including merge-boundary records created while the branch was under review.
+
+Implementation:
+- Coder commits included `191a875`, `591db3f`, `21114fd`, `8fe4b82`, `6ca27f3`, and `a6326a9`.
+- Reviewer approved after fix loops.
+- Merge commit: `634da5d merge: simplify ticket identity fields`.
+
+Validation:
+- Pre-merge and merge-boundary validation passed:
+  - `cargo fmt --check`
+  - `git diff --check`
+  - `cargo run -q -p yoi -- ticket doctor`
+  - `cargo test -p ticket`
+  - `cargo check --workspace`
+  - `nix build .#yoi`
+- After runtime/tooling refresh, new tools also read the flat layout successfully and `cargo run -q -p yoi -- ticket doctor` reports `doctor: ok`.
+
+
 ---