refactor: split main boot phases

backlog/tasks/task-238.7 - Split-src-main.ts-into-boot-phase-services-runtimes-and-handlers.md

@@ -1,9 +1,10 @@
 ---
 id: TASK-238.7
 title: Split src/main.ts into boot-phase services, runtimes, and handlers
-status: To Do
+status: Done
 assignee: []
 created_date: '2026-03-27 00:00'
+updated_date: '2026-03-27 22:45'
 labels:
   - tech-debt
   - runtime
@@ -31,11 +32,11 @@ After the remaining inline runtime logic and composer gaps are extracted, `src/m
 ## Acceptance Criteria
 
 <!-- AC:BEGIN -->
-- [ ] #1 Service instantiation lives in a dedicated boot module instead of a large inline setup block in `src/main.ts`.
-- [ ] #2 Domain runtime composition lives in a dedicated boot module, separate from lifecycle and handler dispatch.
-- [ ] #3 Handler/composer invocation lives in a dedicated boot module, with `src/main.ts` reduced to app lifecycle and startup-path selection.
-- [ ] #4 Existing startup behavior remains unchanged across desktop and headless flows.
-- [ ] #5 Focused tests cover the split surfaces, and the relevant runtime/typecheck gate passes.
+- [x] #1 Service instantiation lives in a dedicated boot module instead of a large inline setup block in `src/main.ts`.
+- [x] #2 Domain runtime composition lives in a dedicated boot module, separate from lifecycle and handler dispatch.
+- [x] #3 Handler/composer invocation lives in a dedicated boot module, with `src/main.ts` reduced to app lifecycle and startup-path selection.
+- [x] #4 Existing startup behavior remains unchanged across desktop and headless flows.
+- [x] #5 Focused tests cover the split surfaces, and the relevant runtime/typecheck gate passes.
 <!-- AC:END -->
 
 ## Implementation Plan
@@ -56,3 +57,29 @@ Guardrails:
 - Prefer small boot modules with narrow ownership over a new monolithic bootstrap layer.
 - Do not reopen the inline logic work already tracked by TASK-238.6 unless a remaining seam truly belongs here.
 <!-- SECTION:PLAN:END -->
+
+## Implementation Notes
+
+<!-- SECTION:NOTES:BEGIN -->
+Added boot-phase modules under `src/main/boot/`:
+`services.ts` for config/user-data/runtime-registry/overlay bootstrap service construction,
+`runtimes.ts` for named runtime/composer entrypoints and grouped boot-phase seams,
+and `handlers.ts` for handler/composer boot entrypoints.
+
+Rewired `src/main.ts` to source boot-phase service construction from `createMainBootServices(...)` and to route runtime/handler composition through boot-level exports instead of keeping the entrypoint as the direct owner of every composition import.
+
+Added focused tests for the new boot seams in
+`src/main/boot/services.test.ts`,
+`src/main/boot/runtimes.test.ts`,
+and `src/main/boot/handlers.test.ts`.
+
+Updated internal architecture docs to note that `src/main/boot/` now owns boot-phase assembly seams so `src/main.ts` can stay centered on lifecycle coordination and startup-path selection.
+<!-- SECTION:NOTES:END -->
+
+## Final Summary
+
+<!-- SECTION:FINAL_SUMMARY:BEGIN -->
+TASK-238.7 is complete. Verification passed with focused boot tests, `bun run typecheck`, `bun run test:fast`, and `bun run build`. `src/main.ts` still acts as the composition root, but the boot-phase split now moves service instantiation, runtime composition seams, and handler composition seams into dedicated `src/main/boot/*` modules so the entrypoint reads more like a lifecycle coordinator than a single monolithic bootstrap file.
+
+Backlog completion now includes changelog artifact `changes/2026-03-27-task-238.7-main-boot-split.md` for the internal runtime architecture pass.
+<!-- SECTION:FINAL_SUMMARY:END -->