docs: record the target-dir symlink coupling and refresh stale provenance

The disk risk in the roadmap described a situation that no longer exists (12G
free, no monorepo build yet). Replaced with the real standing risk: sl0ppij/target
is a symlink into the old ~/lol/zellij checkout, so deleting that checkout breaks
builds until 'rm sl0ppij/target && make build plugins'.

1 files changed, 18 insertions, 5 deletions

diff --git a/docs/roadmap.md b/docs/roadmap.md
index e5964d6..26f6680 100644
--- a/docs/roadmap.md
+++ b/docs/roadmap.md
@@ -86,11 +86,24 @@ URL.
 
 ## Standing risks
 
-**Disk.** `~/lol/zellij/target` is 17G and this box has ~12G free. A release
-build in the monorepo creates a *second* target dir of similar size. Once the
-monorepo is confirmed authoritative, delete the old fork checkout's target dir
-(or the checkout itself — its history is preserved here and on
-`git.sl0p.foo`). Until then, `make build` may fail on ENOSPC.
+**`sl0ppij/target` is a symlink to `~/lol/zellij/target`.** Introduced when the
+box had 12G free, to reuse the old checkout's compiled dependencies instead of
+building a second multi-GB tree. `CARGO_TARGET_DIR` alone was not enough,
+because the debug-plugin `include!` path resolves relative to the source tree.
+
+This is the one thing tying the monorepo to the old checkout: **deleting
+`~/lol/zellij` leaves a dangling symlink and confusing build errors.** To cut the
+cord (costs one ~5min cold release build):
+
+```bash
+rm sl0ppij/target && make build plugins
+```
+
+`sl0pstatus/target` is already a real directory (572M).
+
+**Release builds are slow by design.** `make build` is 5m16s here (LTO,
+`codegen-units = 1`); `make dev` is the ~3s iteration loop. Do not put `make
+build` in an edit cycle.
 
 **pi version coupling.** `pi-ext/` targets pi's extension API, pinned at 0.84.1.
 Bumping the pin is an integration test, not a version bump.