ticket: split backend runtime registry integration

.yoi/tickets/00001KVZKSV6C/thread.md

@@ -4,4 +4,41 @@
 
 LocalTicketBackend によって作成されました。
 
+---
+
+<!-- event: decision author: hare at: 2026-06-25T16:27:28Z -->
+
+## Decision
+
+Decision update: split Backend Runtime work into three implementation tickets.
+
+1. 00001KVZKSV6C Backend RuntimeRegistryの基盤をworker-runtime向けに整理する
+   - Registry identity/projection/error boundary only.
+   - No embedded Runtime handle implementation.
+   - No remote Runtime client implementation.
+2. 00001KVZSGT0Q Backend RuntimeRegistryにembedded worker-runtimeを接続する
+   - Direct lib-call integration for backend-internal Runtime.
+3. 00001KVZSGT14 Backend RuntimeRegistryにremote worker-runtime processを接続する
+   - HTTP/event-stream client integration for remote Runtime processes.
+
+Companion Web Console depends on embedded integration, not remote integration.
+
+
+---
+
+<!-- event: intake_summary author: hare at: 2026-06-25T16:30:31Z -->
+
+## Intake summary
+
+Marked ready by `yoi ticket state`.
+
+---
+
+<!-- event: state_changed author: "yoi ticket" at: 2026-06-25T16:30:31Z from: planning to: ready reason: cli_state field: state -->
+
+## State changed
+
+Marked ready by `yoi ticket state`.
+
+
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