feat(templates): drop the worktree from the delivery rule and §9

design/orchestration.md

@@ -779,15 +779,16 @@ Each unit of work — a spec, or a plan's leaf — gets its own branch, cut from
 `main` and clean once the work has landed. That last part is the whole discipline: the
 next unit of work starts where this one did.
 
-**A git worktree is not part of this, and used to be.** It was there for one case —
-**the user running several Claude Code sessions at once**, one per feature, each
-needing a directory of its own, since a shared tree with `git switch` would have two
-sessions fighting over one working directory. That case is real and still supported.
-But it is the user's setup to make, once, for the runs they actually parallelize, and
-making it a step of the ordinary procedure charged every single-session run for it: a
-directory to create, one to switch into, one to remember to remove, and a stale
-checkout left behind whenever a run died before the last step. What survives is the
-line the worktree was really carrying — leave the checkout clean, on `main`.
+**Nothing here needs a second directory, and the procedure used to make one.** It was
+there for one case — **the user running several Claude Code sessions at once**, one per
+feature, each needing a directory of its own, since a shared tree with `git switch`
+would have two sessions fighting over one working directory. That case is real and
+still supported, but arranging it is the user's own setup, made once for the runs they
+actually parallelize. Making it a step of the ordinary procedure charged every
+single-session run for it: a directory to create, one to switch into, one to remember
+to remove, and a stale checkout left behind whenever a run died before the last step.
+What survives is the line that setup was really carrying — leave the checkout clean, on
+`main`.
 
 So parallelism is back, and it is worth being precise about why this version is fine
 when §8's was not. **The user drives this one; the orchestrator drove that one.** Four
@@ -808,12 +809,12 @@ within each session the accumulated context prevents it outright. The risk drops
 
 ### What running several sessions still costs
 
-Separate checkouts isolate files. They do not isolate the world outside them, so two of
+Separate sessions isolate files. They do not isolate the world outside them, so two of
 these concerns from §8 survive at feature granularity and should be said plainly:
 
 - **Shared external resources.** Two sessions running the suite at the same time will
   fight over a fixed port, one test database, or a shared temp path. Either the suite
-  namespaces those per checkout, or the test runs have to be serialized. Nothing about
+  namespaces those per session, or the test runs have to be serialized. Nothing about
   a separate directory fixes this.
 - **Cross-feature breakage.** Two features green on their own branches can be broken
   together. Only CI on `main` after the merge sees that — which is a good reason to

internal/assets/assets.go

@@ -131,7 +131,13 @@ import (
 // pointed at, and what nobody can justify is reported by name instead of filled in. The
 // ADRs are last and strictest for that reason, and each says in its `## Context` that it
 // was reconstructed after the fact.
-const Version = "17"
+// 18: delivery.md stops naming a second-directory setup at all. Version 15 took it out
+// of the procedure and left the rule pointing at one anyway, which is the same cost in
+// a smaller font: a line preloaded into every request, describing a step nothing in the
+// flow performs. How a user arranges several sessions against one repo is theirs, and
+// saying so is enough — the rule keeps only what it was ever really carrying, which is
+// to leave the checkout back on `main` and clean.
+const Version = "18"
 
 // The embedded tree. "all:" so nothing is silently dropped for having a name the
 // default embed pattern skips.

internal/assets/templates/rules/delivery.md

@@ -8,8 +8,8 @@ git switch -c <type>/<slug>
 ```
 
 Branch from a green `main`, and leave the checkout back on `main` and clean once the
-work lands. Nothing here needs a second directory: a user running several sessions
-against one repo may give each its own `git worktree`, and that is theirs to set up.
+work lands. Nothing here needs a second directory: how a user runs several sessions
+against one repo at once is theirs to set up.
 
 ## Implementation is sequential — you write the code