docs: add execution roadmap workflow

AGENTS.md

@@ -10,6 +10,7 @@ Before starting substantial work, read the roadmap that matches the task:
 
 - implementation work: [docs/implementation-roadmap.md](/home/kurihada/project/ai-workflow-skill/docs/implementation-roadmap.md)
 - inbox Markdown test-plan work: [docs/tests/inbox/ROADMAP.md](/home/kurihada/project/ai-workflow-skill/docs/tests/inbox/ROADMAP.md)
+- execution-trace workflow: [docs/roadmaps/README.md](/home/kurihada/project/ai-workflow-skill/docs/roadmaps/README.md)
 
 ## Roadmap Update Rule
 
@@ -25,6 +26,16 @@ Required behavior:
 - when a test case is written, update authored-case tracking and pending backlog
 - when a planned item is no longer needed, mark it as removed or deferred instead of silently dropping it
 
+For substantial multi-step work, also keep an execution roadmap under [docs/roadmaps/active/](/home/kurihada/project/ai-workflow-skill/docs/roadmaps/active/) while the work is in progress, then move it to [docs/roadmaps/archive/](/home/kurihada/project/ai-workflow-skill/docs/roadmaps/archive/) when the work is complete.
+
+Required behavior for execution roadmaps:
+
+- before starting substantial multi-step work, create or adopt one roadmap file under [docs/roadmaps/active/](/home/kurihada/project/ai-workflow-skill/docs/roadmaps/active/)
+- write the intended task as checklist items and keep them updated as work progresses
+- if work is unfinished, blocked, or paused, leave the roadmap in `active/` with current status and next step
+- when all checklist items are complete, add a completion summary and move the file to `archive/` in the same change
+- use stable slug filenames and prefer one roadmap file per workstream rather than one file per tiny action
+
 ## Inbox Test-Plan Specific Rule
 
 For `docs/tests/inbox/`: