feat: rules for where an app's windows open, and auto-filled zones

[ostapondo]

What changed, and why

Rules for where an app's windows open. Pick an app on the Zones page, a zone, and if you want a monitor, and every new window of that app lands there. Stored by display UUID, so it survives a relaunch and a reboot that renumbers the screens. Wins over the "where the last one went" habit when both apply.

Also a switch that drops a new window with no rule and no habit into the first empty zone. Off by default.

Agents get set_app_rule and clear_app_rule, and app_rules in get_state. README tool count goes from 20 to 22.

Two side changes: the app picker from the exclusions list is now AppAdder so the rules list can reuse it, and mcp/src/api.ts was at the 300-line limit, so its response types moved to types.ts.

What you ran

(cd App && swift build)
./scripts/test.sh                 497 pass, 16 new
./scripts/lint.sh
(cd mcp && npm ci && npm test)    32 pass
node scripts/check-strings.mjs

Checks

• swift build passes on every commit in the branch
• New logic is covered: AppRuleTests, AppRuleRoutesTests
• Conventional commits
• Nothing touches the network, permissions, entitlements or the update path
• No screenshots yet; the new card is "Where apps open" on the Zones page

If this moves windows

Setup: macOS 26, one built-in display at 2x, Halves.

• One screen. Rule TextEdit to zone 2 over the API, then testbench.sh up 1: the window landed in zone 2.
• Put it back: not touched.
• Second monitor: no hardware. A rule for a display that is not attached falls back to the screen the window opened on.
• Mixed scale factors: no hardware.
• Unplug and plug back in: no hardware.
• Excluded app: the watcher checks the exclusion list before placing, as before.

screen 0  1728x1084
  plonk-bench-1.txt      screen 0  x 0.510  y 0.010  w 0.490  h 0.980