feat(flake): #134 — unstable.<pkg> in the downstream, one input, no hand pins

Nomarchy now carries a nixpkgs-unstable input and exposes it through
overlays.default as an `unstable` attrset: in the template's
`home.packages = with pkgs; [ … ]` a user writes `unstable.lmstudio`
and is done. Downstream stays one locked input; nomarchy-pull moves it.
lib.nix needed zero changes — mkFlake's pkgs already applies the
overlay. The import is plain and non-recursive, so configs that never
reference unstable. pay nothing beyond the input fetch; allowUnfree
mirrors the base set so the motivating lmstudio resolves.

Home packages are the supported surface (documented convention). Costs
stated in the README, not hidden: you own the pinned+unstable
combination; a second toolchain lands in your closure (~690 of ~4k
paths shared, measured on lmstudio); it moves when the lock moves.
Lock bumps now move two channels — VERIFICATION §5 and CONVENTIONS
updated accordingly. flake.lock gained exactly one node
(nixos-unstable @ 753cc8a); nothing else moved.

Verification: V1 — nix flake check --no-build green; new eval-only
checks.unstable-seam green (26.05pre vs 26.11pre lib.version, no
builds); template HM activation built via mkFlake with unstable.hello
enabled and its closure carries the unstable store path (pg2zfr… vs
pinned nm7p8w…). Implementation by a Sonnet subagent; design and
review on Fable.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

agent/BACKLOG.md

@@ -89,29 +89,6 @@ rofi#2317, and take the fix when a release carries it. If it is still open at
 the next lock bump, that is fine — nothing here rots meanwhile.
 *Last checked 2026-07-17: open, no maintainer response, no linked PR.*
 
-### 134. `unstable.<pkg>` in the downstream — decided, build it
-
-**Decided 2026-07-17 (Bernardo): Nomarchy carries the channel.** Add a
-`nixpkgs-unstable` input to the distro flake and expose it through
-`overlays.default` as an `unstable` attrset, so
-`home.packages = [ unstable.lmstudio ];` just works — downstream stays one
-locked input and `nomarchy-pull` still moves it. Scope is **home packages
-only**; no `unstable.*` surface in system.nix, no `stable.` synonym for now.
-The input rides in the eval unconditionally (an unused input still locks +
-fetches — accepted). Original diagnosis stands: `mkFlake` has no overlay
-seam and `homeConfigurations` uses mkFlake's own `pkgs`, so nothing short of
-the distro carrying the channel keeps the user out of `fetchTarball` pinning.
-
-Costs accepted with the ruling, to be stated in docs, not hidden: lock bumps
-now move two channels (VERIFICATION §5 full-checklist applies to both); a
-user who reaches for `unstable.` pays a second stdenv/glibc in their closure
-(measured: lmstudio shares only ~690 of ~3.7–4k paths); and nothing upstream
-tests pinned-Nomarchy + unstable-app together — the README needs an explicit
-"you own this combination" paragraph. Ship with a commented example in
-`templates/downstream/home.nix` (opt-in convention) and a README table note.
-Pass = flake check green + a V1 build of the template HM closure with one
-`unstable.` package enabled. Related: #133.
-
 ## LATER
 
 - **Wallpapers artifact split** (ROADMAP § Faster switches — decided,
@@ -312,7 +289,7 @@ decide. **Resolved** entries stay for history; agents treat them as closed.
   is promoted, a public binary cache (cachix) is the likely first step.
 - **#134 unstable packages** — build it: Nomarchy carries the
   `nixpkgs-unstable` input, `unstable.*` via the overlay, home-scope only.
-  Moved to NEXT with the full decided shape.
+  Shipped the same day (ROADMAP § `unstable.<pkg>` in the downstream).
 - **#114 greeter layouts** — document only: a VT has one keymap by design,
   so tuigreet cannot honour per-device layouts. Shipped as the README
   "Greeter keyboard layout" note + a RECOVERY.md pointer; entry deleted.

agent/CONVENTIONS.md

@@ -68,5 +68,7 @@ those, it probably shouldn't exist.
 - Commit style: `feat|fix|test|docs|chore(scope): summary`, body with
   what/why + verification tier + what remains. Bookkeeping (`agent/`
   updates) rides in the same commit as the change.
-- `flake.lock` moves only when the task *is* a lock bump, and only within
-  the pinned release branches.
+- `flake.lock` moves only when the task *is* a lock bump. The release
+  inputs stay within their pinned release branches; the `nixpkgs-unstable`
+  input (#134, feeds `unstable.*`) tracks `nixos-unstable` and bumps
+  together with the rest — never alone, never `nix flake update`.

agent/JOURNAL.md

@@ -19,6 +19,25 @@ Template:
 
 ---
 
+## 2026-07-17 — #134: `unstable.<pkg>` seam shipped
+- **Task:** BACKLOG #134 (NEXT, decided shape from this morning's triage).
+- **Did:** `nixpkgs-unstable` input + `unstable` attrset in
+  `overlays.default` (plain lazy import, allowUnfree mirrored);
+  `lib.nix` untouched by design — mkFlake's pkgs already applies the
+  overlay. Template opt-in comment (`unstable.lmstudio`), README costs
+  paragraph, `checks.unstable-seam` (eval-only), VERIFICATION §5 +
+  CONVENTIONS two-channel lock rules. Lock gained exactly one node
+  (nixos-unstable @ 753cc8a, 2026-07-15). Sonnet implemented; design +
+  review here.
+- **Verified:** V1 — flake check green; unstable-seam check green
+  (26.05pre vs 26.11pre lib.version); template HM activation built with
+  `unstable.hello` and its closure carries the unstable store path
+  (pg2zfr… vs pinned nm7p8w…).
+- **Pending:** nothing; Bernardo's real-world case is him adding
+  `unstable.lmstudio` to ~/.nomarchy/home.nix whenever he likes.
+- **Next suggestion:** queue is NEXT-empty save watches (#143/#146/#149);
+  NOW holds only the install-findings stub awaiting Bernardo's call.
+
 ## 2026-07-17 — #127 CLOSED: the brick was hypridle eating its own resume path
 - **Task:** BACKLOG #127 (NOW). Two Sonnet forensics passes over the machine's
   journal; interpretation, verdict and close-out here. Bernardo ruled: close +

agent/VERIFICATION.md

@@ -137,7 +137,10 @@ Maintenance follows the same ladder:
 - **Flake lock bumps**: treat as maximum-blast-radius changes. Build,
   boot the VM, run the full regression checklist, and do a visual
   spot-check of the session (themes can shift with upstream package
-  changes). Never merge a lock bump on "it evaluates".
+  changes). Never merge a lock bump on "it evaluates". Since #134 the
+  lock carries **two channels** (the release pin and the
+  `nixos-unstable` pin feeding `unstable.*`) — a bump moves both, and
+  this checklist applies to both.
 - **Theme imports / new themes**: import via `tools/import-palettes.py`,
   then the full §3 visual protocol; additionally verify the theme-switch
   round trip (into the new theme and back out).