Add a Gaming page, and let the desktop react to games

Live first, because unlike every other page here this one has a live
dimension: card temperature, power draw, whether Game Mode actually
engaged. It polls only while it is open, since a settings page nobody is
looking at has no business waking the CPU.

The part that makes it Panama's page rather than a gamemode config
editor is the hook. gamemode runs a script when a game asks for it and
another when the game exits, so the power profile switches to
performance and notifications go quiet for exactly the duration of a
game -- and afterwards both go back to what they WERE, not to a default.
A Do Not Disturb someone set by hand survives a game; a power profile
someone chose is restored rather than replaced. Verified against real
gamemode activation, not merely by calling the hook.

Two things the page reports rather than hides. Game Mode's headline
trick is switching the CPU governor to performance, and this machine
already runs performance, so it says so instead of implying it helps.
And Proton builds are listed but never chosen: Steam picks the runtime
per game, and a control here would claim an authority this page does not
have.

The hook first called a notifications function that did not exist, and
the one that did was a TOGGLE -- the wrong primitive entirely, since
toggling at game start would unsilence notifications that were already
silent. The shell gained an explicit setter and reader.

search-routing-contract kept its own hand-written list of every page,
which made adding one fail as "not a known page" -- a sixth place to
register a page and a sixth chance to forget. It now derives the mapping
from the shell, which already knows it.

Claude-Session: https://claude.ai/code/session_01BRvzt4H8XXLPVH5MyYdk9L

docs/settings.md

@@ -4,7 +4,7 @@
 Do not edit this file. Run `quickshell/scripts/panama-settings-docs`
 after changing the schema; a contract fails when this copy is stale.
 
-128 settings across 26 groups. 67 of them are applied to the compositor and confirmed by reading the value back.
+131 settings across 27 groups. 67 of them are applied to the compositor and confirmed by reading the value back.
 
 ## accessibility
 
@@ -108,6 +108,16 @@ Found on **Desktop & Dock**.
 |---|---|---|
 | **Focus session length**<br>`focusDurationMinutes` | 45 min | How long a focus session runs before it ends itself. Range 5–180. |
 
+## gaming
+
+Found on **gaming**.
+
+| Setting | Default | What it does |
+|---|---|---|
+| **Use the performance power profile**<br>`gamingPerformanceProfile` | true | Switches while a game runs and switches back when it exits |
+| **Silence notifications**<br>`gamingSilenceNotifications` | true | Do Not Disturb for the duration, so nothing steals focus mid-game. A Do Not Disturb you set yourself is left alone. |
+| **Say when Game Mode engages**<br>`gamingNotifyOnStart` | false | A notification when a game requests it, which is otherwise invisible |
+
 ## idle
 
 Found on **Power & Lock**.

docs/superpowers/plans/2026-08-19-settings-beyond-gnome.md

@@ -200,6 +200,29 @@ where the library lives.
 should own the handful of things that are actually settings and link out for the
 rest.
 
+**Landed 2026-08-19.** Live-first, because unlike every other page here this one
+has a genuinely live dimension: card temperature, power draw, whether Game Mode
+actually engaged. It polls only while it is open.
+
+The part that makes it Panama's page rather than a gamemode config editor is the
+hook. gamemode runs a script when a game asks for it and another when the game
+exits, so the power profile switches to performance and notifications go quiet
+for exactly the duration of a game -- and afterwards **both go back to what they
+were, not to a default**. A Do Not Disturb someone set by hand survives a game;
+a power profile someone chose is restored rather than replaced with "balanced".
+Verified with real gamemode activation, not just by calling the hook.
+
+Two honest reports the page makes rather than hides. Game Mode's headline trick
+is switching the CPU governor to performance, and this machine already runs
+performance, so it says the change does nothing here. And Proton builds are
+listed but never chosen: Steam picks the runtime per game, and a control here
+would claim an authority the page does not have.
+
+One bug worth recording. The hook first called a notifications IPC function that
+did not exist, and the one that did exist was a TOGGLE -- which is the wrong
+primitive entirely, because toggling at game start would unsilence notifications
+that were already silenced. The shell gained an explicit setter and reader.
+
 ---
 
 ## Batch 4 — The developer surface