macos: pixel attachments, live theming, and a signed app

The AppKit shell now draws what the core renders, follows the theme without a
relaunch, and builds into something you can hand to someone.

- Pixel attachments. Surface.images was dropped on the floor here, so a PDF
  pane showed nothing at all: native_images is now set, pardes_image_s carries
  the geometry the core already clipped, and PardesView keeps one CGImage per
  (serial, page, revision) so scrolling costs a draw and not a decode. Image
  panes get real pixels instead of the petscii fallback.

- Themes take hold live. pardes_tick never advanced the chrome animation, so
  every tagline kept the previous theme's colours until the next launch and
  the 16 ms re-pump spun for the rest of the session. pardes_theme_bg retires
  the hand-agreed #121212 and drives the window background and the titlebar
  appearance; a theme with no background of its own now gets a transparent
  window over an NSVisualEffectView.

- The cell snaps to whole DEVICE pixels rather than whole points. Monaco
  advances 8.4014pt at 14, so ceiling to 9 spaced every column 7.1% wider than
  the face was drawn for.

- The dial is one notch per 10 degrees instead of 20, and a release keeps
  turning in proportion to how hard it was thrown -- ramping up from zero at
  the floor, so a slow twist coasts not a little but not at all.

- A file dropped on the grid is a click plus Look, so it opens beside the pane
  it was dropped on. No drop concept was added to the core.

- The titlebar follows the focused pane: proxy icon, filename, and the dirty
  dot. File.saved_revision is the watermark that last one needed.

- Config (SPC f c) prints the resolved startup config path.

- build.zig assembles, signs and packages the bundle itself; build-app.sh is
  gone. -Dmacos-identity= takes a Developer ID, macos-dmg makes the image, and
  the icon is Glenda.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/macos/Info.plist b/src/macos/Info.plist
index 665d54ca..3d526242 100644
--- a/src/macos/Info.plist
+++ b/src/macos/Info.plist
@@ -17,16 +17,16 @@
 	<key>CFBundleVersion</key>
 	<string>1</string>
 	<!-- No extension: Launch Services appends .icns and looks in
-	     Contents/Resources, where build-app.sh emits pardes.icns. Without this
-	     key the Dock shows the blank generic app even though the icon is
-	     sitting right there in the bundle. -->
+	     Contents/Resources, where build.zig installs the pardes.icns
+	     src/macos/icon.swift draws. Without this key the Dock shows the blank
+	     generic app even though the icon is sitting right there in the bundle. -->
 	<key>CFBundleIconFile</key>
 	<string>pardes</string>
 	<key>NSHighResolutionCapable</key>
 	<true/>
-	<!-- build-app.sh overwrites this from macos_min_version in build.zig, which
-	     is the single source of truth; the key must exist for PlistBuddy's Set
-	     to have something to set. -->
+	<!-- build.zig stamps this from macos_min_version, which is the single
+	     source of truth, into a copy of this file; the key must exist for
+	     plutil's -replace to have something to replace. -->
 	<key>LSMinimumSystemVersion</key>
 	<string>13.0</string>
 	<key>LSApplicationCategoryType</key>