Merge pull request #2086 from obra/fix/spec-travels-with-plan

fix(planning): the spec travels with the plan

skills/subagent-driven-development/SKILL.md

@@ -154,7 +154,10 @@ a ledger file, not only in todos.
   that happens, recover from `git log`.
 
 Read the plan once, note its context and Global Constraints, and create a
-todo per task.
+todo per task. If the plan names a Spec, read that too: the spec is the
+authority the plan argues from, and conflicts inside the plan resolve
+against it. A plan with no reachable spec gets a ledger note saying so —
+rulings made without one are provisional.
 
 Before dispatching Task 1, scan the plan once for conflicts, writing down
 what you checked as you check it:

skills/writing-plans/SKILL.md

@@ -66,6 +66,9 @@ independently testable deliverable.
 
 **Tech Stack:** [Key technologies/libraries]
 
+**Spec:** [path to the spec/design doc this plan implements — the plan
+argues from the spec, so the spec travels with it; executors read both]
+
 ## Global Constraints
 
 [The spec's project-wide requirements — version floors, dependency limits,