feat(ios,android): P2 wave, git panel, token UX, per-host WS token, docs

App layer, four sequential slices (a shared .xcodeproj means adding files
regenerates it, so these could not run in parallel):

- token UX end to end: pairing prompts for a token when a host 401s, POST /auth
  validates it, and 204-without-Set-Cookie is correctly read as "this server has
  auth disabled" rather than "authenticated". A host paired before the token was
  turned on recovers by re-pairing in place. Remove-host now exists and finally
  gives PushRegistrar.handleHostRemoved a caller.
- project git panel + worktree lifecycle (T-iOS-32) + claude --resume history —
  the parity gap with Android and the web front end.
- terminal search (T-iOS-33) and voice PTT (T-iOS-31) with an epoch guard so a
  session switch between dictation and confirm cannot inject into the wrong
  session.
- theme + Dynamic Type (T-iOS-34) and web ?join= interop (T-iOS-35). RootView no
  longer hard-locks .preferredColorScheme(.dark).

Also unpins SwiftTerm to 1.15.0 by dropping the local hasActiveSelection that
collided with the upstream one, verified green from a fresh derivedDataPath.

Includes the two HIGH fixes the security review found:
- iOS resolved the WS token host-independently, so a token-gated host sitting
  next to an open one could never open a terminal and no on-screen remedy could
  fix it. Now one transport per host; cross-host leakage is structurally
  impossible since both read paths return only that host's own value.
- Android reported the host's own git-credential 401 (git-ops.ts:108, "Push
  authentication required on the host.") as "your access token is wrong", because
  a blanket 401 mapping ran ahead of the per-route one. Git-write routes are now
  ROUTE_DEFINED and keep the server's message.

And the doc sync: README/ios README no longer claim the client is unmerged on
feat/ios-client, the Clients section finally lists Android, and the plan
checkboxes reflect what is actually built.

iOS 534 app tests + 452 package tests; Android 687 tests.

ios/App/WebTerm/Screens/SettingsScreen.swift

@@ -0,0 +1,122 @@
+import SwiftUI
+
+/// T-iOS-34 · 设置页 —— 目前只有一件事：**主题**（跟随系统 / 深色 / 浅色）。
+///
+/// 刻意不做成「一堆开关」：终端字号跟随系统 Dynamic Type（`TerminalTheme` 取
+/// `.footnote` 度量），主机/令牌在配对页，快捷键栏在终端工具栏 —— 那些都有更近
+/// 的入口，搬到这里只会多一条重复路径。
+///
+/// 选择即生效：`ThemeStore.select` 落盘 + `@Observable` 触发根视图重算
+/// `preferredColorScheme`，不需要「保存」按钮。
+struct SettingsScreen: View {
+    /// 主题真值（`RootView` 持有并注入；这里只读写它，不自己存一份）。
+    let themeStore: ThemeStore
+
+    /// 当前**有效**外观 —— 根视图的 `preferredColorScheme` 已经把它压进了环境，
+    /// 所以终端预览直接读环境即可，不必再算一遍「跟随系统时到底是哪档」。
+    @Environment(\.colorScheme) private var effectiveScheme
+
+    var body: some View {
+        List {
+            themeSection
+            terminalPreviewSection
+        }
+        .navigationTitle(SettingsCopy.title)
+    }
+
+    // MARK: - 主题选择
+
+    private var themeSection: some View {
+        Section {
+            ForEach(AppTheme.allCases, id: \.self) { theme in
+                themeRow(theme)
+            }
+        } header: {
+            Text(SettingsCopy.themeHeader)
+        } footer: {
+            Text(SettingsCopy.themeFooter)
+        }
+    }
+
+    private func themeRow(_ theme: AppTheme) -> some View {
+        Button {
+            themeStore.select(theme)
+            DS.Haptics.selection()
+        } label: {
+            HStack(spacing: DS.Space.md12) {
+                Image(systemName: theme.symbolName)
+                    .foregroundStyle(DS.Palette.accent)
+                    .frame(width: DS.Space.xxl24)
+                Text(theme.label)
+                    .foregroundStyle(DS.Palette.textPrimary)
+                Spacer(minLength: DS.Space.sm8)
+                if themeStore.theme == theme {
+                    Image(systemName: "checkmark")
+                        .foregroundStyle(DS.Palette.accent)
+                        .fontWeight(.semibold)
+                }
+            }
+            .frame(minHeight: DS.Layout.minHitTarget)
+        }
+        .accessibilityIdentifier("settings.theme.\(theme.rawValue)")
+        // 选中态对 VoiceOver 可见（勾号是视觉信号，不是语义信号）。
+        .accessibilityAddTraits(themeStore.theme == theme ? [.isSelected] : [])
+    }
+
+    // MARK: - 终端画布预览
+
+    /// 主题的最大可见差异就是终端那一整块画布，所以给一个真实取色的预览条：
+    /// 背景/前景/光标全部来自 `TerminalPalette`（与真终端同一出处）。
+    private var terminalPreviewSection: some View {
+        Section {
+            let colors = TerminalPalette.colors(for: effectiveScheme)
+            HStack(spacing: DS.Space.xs2) {
+                Text(verbatim: SettingsCopy.terminalSample)
+                    .font(DS.Typography.mono(.footnote))
+                    .foregroundStyle(Color(uiColor: colors.foreground))
+                Rectangle()
+                    .fill(Color(uiColor: colors.caret))
+                    .frame(width: DS.Space.sm8, height: DS.Space.lg16)
+                Spacer(minLength: 0)
+            }
+            .padding(DS.Space.md12)
+            .background(
+                Color(uiColor: colors.background),
+                in: RoundedRectangle(cornerRadius: DS.Radius.sm8)
+            )
+            .accessibilityElement(children: .ignore)
+            .accessibilityLabel(SettingsCopy.terminalPreviewA11y)
+        } header: {
+            Text(SettingsCopy.terminalHeader)
+        }
+    }
+}
+
+/// 设置页用户可见文案。
+enum SettingsCopy {
+    static let title = "设置"
+    static let themeHeader = "外观"
+    static let themeFooter = "默认深色 —— 与网页端一致。选「跟随系统」时随 iOS 的浅色/深色切换。"
+    static let terminalHeader = "终端预览"
+    static let terminalSample = "$ claude --resume"
+    static let terminalPreviewA11y = "终端配色预览"
+}
+
+// MARK: - Previews
+
+#Preview("SettingsScreen") {
+    NavigationStack {
+        SettingsScreen(themeStore: ThemeStore(defaults: PreviewThemeDefaults()))
+    }
+}
+
+/// 预览用的内存 defaults —— 预览绝不写用户的真实 `UserDefaults`。
+private final class PreviewThemeDefaults: ThemeDefaults {
+    private var values: [String: String] = [:]
+
+    func themeRaw(forKey key: String) -> String? { values[key] }
+
+    func setThemeRaw(_ value: String, forKey key: String) {
+        values = values.merging([key: value]) { _, new in new }
+    }
+}