M2 follow-up: Citadel 0.12.1 (current), pre-built Assets.xcassets

Two follow-ups per review:

## Citadel: current stable

Citadel is at 0.12.1, not 0.9.x as I'd been writing against. Bumped
the pin from `from: "0.7.0"` to `.upToNextMinor(from: "0.12.0")`
— tight because Citadel's pre-1.0 authentication-method variants
have shifted between minor releases (0.7 → 0.9 → 0.12), so
explicit bump-and-review is safer than letting the version float.

Downloaded Citadel 0.12.1's source and verified every API call in
CitadelSSHService against it:
  - SSHAuthenticationMethod.ed25519(username:, privateKey:) ✓
  - SSHClientSettings(host:, authenticationMethod:, hostKeyValidator:) ✓
  - SSHHostKeyValidator.acceptAnything() ✓
  - SSHClient.connect(to: settings) ✓
  - client.executeCommand(_:) -> ByteBuffer ✓
  - client.close() async throws ✓

Dropped the "FIXME — may need adjustment" disclaimer in the file
header; replaced with a "verified against 0.12.1" note that says
re-verify if the pin bumps to 0.13+. Same change in SETUP.md
troubleshooting.

## Assets.xcassets (app icon + accent color)

scarf/scarf-ios/Assets.xcassets/ now exists with:

  - AppIcon.appiconset/
      AppIcon-1024.png    (1024×1024, copied from the Mac app's
                           icon set — same art)
      Contents.json       (idiom: universal, platform: ios,
                           size: 1024x1024 — iOS 14+ renders all
                           smaller sizes from this automatically)
  - AccentColor.colorset/
      Contents.json       (Scarf teal: sRGB 0.227/0.525/0.722
                           light, 0.400/0.690/0.902 dark)
  - Contents.json         (root, empty — just version metadata)

SETUP.md updated:
  - Instructs Alan to delete Xcode's scaffolded Assets.xcassets AND
    import ours, not the other way around.
  - Notes the accent color values so a different palette choice is
    a one-file edit.
  - Removes the obsolete "drop your icon asset" step.

No functional code changes; tests still 88/88 on Linux.

https://claude.ai/code/session_019yMRP6mwZWfzVrPTqevx2y

scarf/Packages/ScarfIOS/Package.swift

@@ -32,11 +32,15 @@ let package = Package(
     ],
     dependencies: [
         .package(path: "../ScarfCore"),
-        // Pinned to the 0.7 minor line until the API stabilizes at 1.0.
-        // When we bump, re-run onboarding smoke tests against at least:
+        // Pinned tight to the 0.12 minor line. Citadel pre-1.0 has
+        // changed its authentication-method variant names between
+        // minor versions (0.7 → 0.9 → 0.12) — letting the version
+        // float to 0.13+ without a code review risks a silent build
+        // break in `CitadelSSHService.buildClientSettings(...)`. When
+        // bumping the minor, smoke test onboarding against:
         //   (a) a real host with 1Password SSH agent
         //   (b) a real host with a hand-edited `authorized_keys`
-        .package(url: "https://github.com/orlandos-nl/Citadel", from: "0.7.0"),
+        .package(url: "https://github.com/orlandos-nl/Citadel", .upToNextMinor(from: "0.12.0")),
     ],
     targets: [
         .target(

scarf/Packages/ScarfIOS/Sources/ScarfIOS/CitadelSSHService.swift

@@ -20,14 +20,15 @@ import ScarfCore
 ///     (file transport, SQLite snapshot pulls, ACP channel) will
 ///     layer on top.
 ///
-/// **Citadel API disclaimer.** Citadel 0.9's exact authentication-
-/// method spelling for Ed25519 private keys is evolving across
-/// 0.7 → 0.9. The `runOneShotProbe(...)` helper below is written
-/// against the documented `SSHClientSettings` + `.privateKey(...)`
-/// pattern; if Citadel has renamed or refactored that variant,
-/// adjust `buildClientSettings(...)` — everything else (the retry
-/// loop, the error classification, the exit-code handling) is
-/// Citadel-version-independent.
+/// **Citadel 0.12.1 API verified.** Every call below (`SSHAuthentication
+/// Method.ed25519(username:privateKey:)`, `SSHClientSettings(host:
+/// authenticationMethod:hostKeyValidator:)`, `SSHHostKeyValidator.
+/// acceptAnything()`, `SSHClient.connect(to:)`, `client.executeCommand
+/// (_:)`, `client.close()`) was cross-checked against the 0.12.1 tag in
+/// April 2026. If Citadel's package pin is bumped to a new minor
+/// (0.13+), re-verify these against
+/// `Sources/Citadel/SSHAuthenticationMethod.swift` and
+/// `Sources/Citadel/ClientSession.swift` in the new release.
 public struct CitadelSSHService: SSHConnectionTester {
     /// Seconds to wait for the probe exec. Set tight so onboarding
     /// doesn't hang on a silently-dropped connection.
@@ -116,15 +117,10 @@ public struct CitadelSSHService: SSHConnectionTester {
     // MARK: - Citadel glue
 
     /// Translate our in-house `SSHKeyBundle` (raw 32+32 byte Ed25519)
-    /// into Citadel's authentication method.
-    ///
-    /// **FIXME when updating Citadel.** The exact function name below
-    /// is my best read of Citadel 0.7–0.9's API surface — private-key
-    /// auth has gone through several iterations. If the build fails
-    /// here with "no member `ed25519`" or similar, check the current
-    /// `SSHAuthenticationMethod.swift` in the pinned Citadel version
-    /// and adjust. Everything else (key decode, error classification,
-    /// timeout) is independent.
+    /// into Citadel's authentication method. Verified against Citadel
+    /// 0.12.1 — see `Sources/Citadel/SSHAuthenticationMethod.swift`
+    /// for the full set of `.passwordBased(...)` / `.ed25519(...)` /
+    /// `.p256(...)` / etc. variants.
     private func buildClientSettings(
         config: IOSServerConfig,
         key: SSHKeyBundle
@@ -138,9 +134,6 @@ public struct CitadelSSHService: SSHConnectionTester {
             throw SSHConnectionTestError.other("Stored private key is malformed")
         }
         let username = config.user ?? "root"
-        // See FIXME above — the `.ed25519(...)` method name is the
-        // shape I expect based on Citadel 0.7–0.9 docs; double-check
-        // on Mac once the pod is resolved.
         let auth: SSHAuthenticationMethod = .ed25519(
             username: username,
             privateKey: ck