diff --git a/agent/JOURNAL.md b/agent/JOURNAL.md
index ccc070a..e7fafce 100644
--- a/agent/JOURNAL.md
+++ b/agent/JOURNAL.md
@@ -17,6 +17,23 @@ Template:
 
 ---
 
+## 2026-07-09 — Fix Hyprland windowrule config-error banner (windowrule 0.53 migration)
+- **Task:** bug tripped over while doing #45 (VM Boreal verify) — the default
+  desktop showed a red Hyprland config-error banner on every boot, occluding
+  the Waybar.
+- **Did:** Root-caused via the theme-shot harness + Hyprland 0.55.4 source
+  (`handleWindowrule`): Hyprland 0.53 rewrote window rules — `windowrulev2` is a
+  hard error and the old rule-first `float, class:^…$` order no longer parses
+  (so the float rules weren't even applying). Migrated the 7-rule block in
+  `modules/home/hyprland.nix` to the new hyprlang grammar `<effect> <value>,
+  match:<prop> ^…$` (e.g. `float 1, match:class ^…$`).
+- **Verified:** V0 `nix flake check --no-build` green; built the generated
+  `hyprland.conf` and confirmed emitted lines; **V2** theme-shot re-render —
+  banner gone, themed Waybar now renders (violet accent, GeistMono clock).
+- **Pending:** none for the fix. A cheap `checks.*` that greps the generated
+  conf for the dead rule-first pattern could lock it (PROPOSED).
+- **Next suggestion:** finish #45 (capture boreal preview.png), then #46.
+
 ## 2026-07-09 — Default theme → Boreal (item #42)
 - **Task:** NEXT #42 — distro default theme Tokyo Night → Boreal (`VISION § B` / v1.0 bar).
 - **Did:** Seeded `theme-state.json` + `templates/downstream/theme-state.json` from `themes/boreal.json` (incl. border + settings). Eval fallbacks: `theme.nix` preset → boreal.json; plymouth + live ISO splash hex fallbacks; theme-shot / theme-sync examples; TESTING/RECOVERY wording.
diff --git a/agent/MEMORY.md b/agent/MEMORY.md
index b533d53..99902ce 100644
--- a/agent/MEMORY.md
+++ b/agent/MEMORY.md
@@ -103,6 +103,11 @@ iteration would otherwise rediscover.
 - Update order matters downstream: `sys-update` (lock) before
   `home-update`, or desktop changes are silently skipped against the old
   lock (README § 3).
+- Hyprland 0.53 rewrote window rules: `windowrulev2` is a hard error and
+  the old rule-first `float, class:^…$` no longer parses — both surface a
+  red config-error banner on the default desktop. Hyprlang legacy form is
+  now `<effect> <value>, match:<prop> ^…$` (e.g. `float 1, match:class ^…$`);
+  effects carry a value, matchers take `match:` (§ windowrule migration).
 - grub `loadfont`s every `.pf2` in a theme dir — reuse a bundled DejaVu
   rather than shipping fonts (§ Distro branding).
 - The Claude Code harness drops machine-local files into the repo
diff --git a/modules/home/hyprland.nix b/modules/home/hyprland.nix
index 4d6b2c2..a85adbf 100644
--- a/modules/home/hyprland.nix
+++ b/modules/home/hyprland.nix
@@ -459,7 +459,14 @@ in
       # Window rules — float + center small config/utility dialogs that
       # tile awkwardly. Normal-priority list like `bind`/`exec-once` below,
       # so a downstream `windowrule = [...]` concatenates rather than
-      # replaces. Class regexes use `(?i)` and tolerate the XWayland
+      # replaces. Syntax is the post-0.53 rule rewrite (hyprlang legacy
+      # parser, `handleWindowrule`): each comma field is `<keyword>
+      # <value>`, so effects carry a value (`float 1`, `center 1`, `size
+      # W H`) and matchers take a `match:` prefix (`match:class ^…$`).
+      # The old rule-first form (`float, class:^…$`) and the
+      # `windowrulev2` key are both hard errors now (red config-error
+      # banner on every session start — seen in the capture harness).
+      # Class regexes use `(?i)` and tolerate the XWayland
       # `.…-wrapped` binary-name form.
       #
       # Conservative set on purpose (item 41): only windows the distro
@@ -468,21 +475,21 @@ in
       # prompt (hyprpolkitagent exposes no discoverable class) and GTK
       # file-chooser portals. A dead rule is harmless, but guessing a class
       # is worse than leaving it for a verified pass.
-      windowrulev2 = [
+      windowrule = [
         # Audio mixer (item 35): right-click the Waybar volume module.
-        "float, class:^(com\\.saivert\\.pwvucontrol|org\\.pulseaudio\\.pavucontrol|pavucontrol)$"
-        "center, class:^(com\\.saivert\\.pwvucontrol|org\\.pulseaudio\\.pavucontrol|pavucontrol)$"
+        "float 1, match:class ^(com\\.saivert\\.pwvucontrol|org\\.pulseaudio\\.pavucontrol|pavucontrol)$"
+        "center 1, match:class ^(com\\.saivert\\.pwvucontrol|org\\.pulseaudio\\.pavucontrol|pavucontrol)$"
 
         # Bluetooth manager (blueman) + CUPS printer admin.
-        "float, class:(?i)^(\\.?blueman-(manager|adapters)(-wrapped)?|\\.?system-config-printer(-wrapped)?)$"
-        "center, class:(?i)^(\\.?blueman-(manager|adapters)(-wrapped)?|\\.?system-config-printer(-wrapped)?)$"
+        "float 1, match:class (?i)^(\\.?blueman-(manager|adapters)(-wrapped)?|\\.?system-config-printer(-wrapped)?)$"
+        "center 1, match:class (?i)^(\\.?blueman-(manager|adapters)(-wrapped)?|\\.?system-config-printer(-wrapped)?)$"
 
         # Calendar popup (item 42): the Waybar clock's on-click runs
         # nomarchy-calendar → calcurse in a ghostty window tagged with a
         # distinct --class, so it floats centered instead of tiling.
-        "float, class:^(com\\.nomarchy\\.calendar)$"
-        "size 60% 65%, class:^(com\\.nomarchy\\.calendar)$"
-        "center, class:^(com\\.nomarchy\\.calendar)$"
+        "float 1, match:class ^(com\\.nomarchy\\.calendar)$"
+        "size 60% 65%, match:class ^(com\\.nomarchy\\.calendar)$"
+        "center 1, match:class ^(com\\.nomarchy\\.calendar)$"
       ];
 
       # Rendered from ./keybinds.nix (the cheatsheet reads the same list),