Rewrite shannoncoat as a native Swift menu-bar app

Replaces the original shannoncoat.sh entirely with in-process Swift. The
script stopped earning its keep once the rest went native, and being a
persistent process rather than a one-shot CLI is what later makes live
window tracking possible at all.

- ProfileStore: JSON config at ~/.shannoncoat/<name>.json (was hand-rolled
  YAML), with ~ expansion, paths relative to the config dir, and
  name/dir-collision validation in one place.
- ProcessInspector: sysctl(KERN_PROC_ALL/KERN_PROCARGS2) enumeration
  instead of shelling out to pgrep.
- ClaudeControl: launch via Process, focus via direct Accessibility calls
  (unhide, un-minimize, poll-for-window, AXRaise) instead of AppleScript,
  and a quit that respects Claude's own termination handling rather than
  unconditionally SIGKILLing after a flat 5s timeout.
- LiveState: NSWorkspace notification-driven state with no polling timer,
  so the menu bar reflects reality within about a second — including
  changes made outside the app entirely.
- ManageWindow: one non-modal window replacing what would otherwise be a
  string of separate popup alerts, with inline add/remove and directory
  pickers.
- LaunchAtLogin / UpdateChecker: SMAppService login-item toggle, and a
  minimal VERSION-file update check that alerts on a manual check and
  posts a quiet notification on the automatic one.

Also drops the standalone CLI in favour of GUI-only, and adds a
placeholder app icon drawn from vector shapes rather than composited on
top of Claude's own icon assets.

Claude Desktop is located at runtime rather than assumed: a path the user
picked previously, then /Applications, then a per-user ~/Applications
install, each accepted only if it actually contains the executable. If
none match, launching a profile asks the user to locate it once and
remembers the answer — a launch that silently does nothing gives them no
way to work out what's wrong.

Sources/ProfileColor.swift

@@ -0,0 +1,39 @@
+// A stable, well-distributed color per profile name, shared by the menu
+// bar dots and the Manage window's profile list so the same name always
+// reads as the same color everywhere.
+import AppKit
+
+enum ProfileColor {
+    // FNV-1a: a proper avalanching hash, not a preset-palette lookup — the
+    // full hue wheel is available, and single-character name edits (e.g.
+    // "personal" vs "personal2") land on unrelated hues instead of an
+    // adjacent bucket the way a plain sum-of-scalars hash mod'd into a
+    // short color list would.
+    private static func fnv1aHash(_ s: String) -> UInt32 {
+        var hash: UInt32 = 0x811c_9dc5
+        for byte in s.utf8 {
+            hash ^= UInt32(byte)
+            hash = hash &* 0x0100_0193
+        }
+        return hash
+    }
+
+    static func dotColor(for name: String) -> NSColor {
+        let hue = CGFloat(fnv1aHash(name) % 360) / 360.0
+        return NSColor(calibratedHue: hue, saturation: 0.65, brightness: 0.9, alpha: 1.0)
+    }
+
+    // `dimmed` marks a profile that isn't actually running right now — the
+    // colored dot still identifies it, but faded, so "open" vs "known but
+    // closed" is visible without reading a tooltip.
+    static func dotImage(for name: String, dimmed: Bool = false) -> NSImage {
+        let size = NSSize(width: 10, height: 10)
+        let image = NSImage(size: size)
+        image.lockFocus()
+        dotColor(for: name).withAlphaComponent(dimmed ? 0.3 : 1.0).setFill()
+        NSBezierPath(ovalIn: NSRect(origin: .zero, size: size)).fill()
+        image.unlockFocus()
+        image.isTemplate = false
+        return image
+    }
+}