fix: sync dev branch with main timeline/schema changes and remove stale providers

Forward-port main's timeline epoch tracking, projected window selection,
and schema updates into dev. Remove aider/amp/gemini providers and
provider-history-compatibility layers that are no longer needed.

packages/app/src/components/icons/aider-icon.tsx

@@ -1,14 +0,0 @@
-import Svg, { Path } from "react-native-svg";
-
-interface AiderIconProps {
-  size?: number;
-  color?: string;
-}
-
-export function AiderIcon({ size = 16, color = "currentColor" }: AiderIconProps) {
-  return (
-    <Svg width={size} height={size} viewBox="0 0 24 24" fill={color}>
-      <Path d="M9 3.75h5.25V4.5H9V3.75Zm-.75.75h6v2.25h-6V4.5Zm6 3h2.25v3h-2.25v-3Zm-6 3h8.25v3h-8.25v-3Zm-1.5 3h1.5v3h-1.5v-3Zm7.5 0h2.25v3h-2.25v-3Zm-6 3h6v3h-6v-3Zm8.25 0H18v3h-1.5v-3Z" />
-    </Svg>
-  );
-}

packages/app/src/components/icons/amp-icon.tsx

@@ -1,29 +0,0 @@
-import Svg, { Path } from "react-native-svg";
-
-interface AmpIconProps {
-  size?: number;
-  color?: string;
-}
-
-export function AmpIcon({ size = 16, color = "currentColor" }: AmpIconProps) {
-  return (
-    <Svg width={size} height={size} viewBox="0 0 24 24" fill="none">
-      <Path
-        fill={color}
-        d="m9.686 6.949 2.907.775-1.98-7.404-3.353.903 1.194 4.49a1.94 1.94 0 0 0 1.232 1.236Z"
-      />
-      <Path
-        fill={color}
-        d="m4.771 22 6.34-6.327 2.307 8.62 3.352-.903L13.432 10.87.912 7.533 0 10.906l8.61 2.3-6.31 6.317L4.77 22Z"
-      />
-      <Path
-        fill={color}
-        d="m13.254 11.707.778 2.917a1.937 1.937 0 0 0 1.23 1.234l4.511 1.199.89-3.37-7.409-1.98Z"
-      />
-      <Path
-        fill={color}
-        d="m15.916 2.484-2.883 2.88a2.063 2.063 0 0 0-.512 1.193l-.046 1.825 1.69.06-.022-.001c.463 0 .898-.181 1.225-.507L18.35 4.95l-2.434-2.467Z"
-      />
-    </Svg>
-  );
-}

packages/app/src/components/icons/gemini-icon.tsx

@@ -1,17 +0,0 @@
-import Svg, { Path } from "react-native-svg";
-
-interface GeminiIconProps {
-  size?: number;
-  color?: string;
-}
-
-export function GeminiIcon({ size = 16, color = "currentColor" }: GeminiIconProps) {
-  return (
-    <Svg width={size} height={size} viewBox="0 0 24 24" fill="none">
-      <Path
-        fill={color}
-        d="M20.616 10.835a14.147 14.147 0 0 1-4.45-3.001 14.111 14.111 0 0 1-3.678-6.452.503.503 0 0 0-.975 0 14.134 14.134 0 0 1-3.679 6.452 14.155 14.155 0 0 1-4.45 3.001c-.65.28-1.318.505-2.002.678a.502.502 0 0 0 0 .975c.684.172 1.35.397 2.002.677a14.147 14.147 0 0 1 4.45 3.001 14.112 14.112 0 0 1 3.679 6.453.502.502 0 0 0 .975 0c.172-.685.397-1.351.677-2.003a14.145 14.145 0 0 1 3.001-4.45 14.113 14.113 0 0 1 6.453-3.678.503.503 0 0 0 0-.975 13.245 13.245 0 0 1-2.003-.678Z"
-      />
-    </Svg>
-  );
-}

packages/app/src/components/provider-icons.ts

@@ -1,9 +1,6 @@
 import { Bot } from "lucide-react-native";
-import { AiderIcon } from "@/components/icons/aider-icon";
-import { AmpIcon } from "@/components/icons/amp-icon";
 import { ClaudeIcon } from "@/components/icons/claude-icon";
 import { CodexIcon } from "@/components/icons/codex-icon";
-import { GeminiIcon } from "@/components/icons/gemini-icon";
 import { CopilotIcon } from "@/components/icons/copilot-icon";
 import { OpenCodeIcon } from "@/components/icons/opencode-icon";
 import { PiIcon } from "@/components/icons/pi-icon";
@@ -11,9 +8,6 @@ import { PiIcon } from "@/components/icons/pi-icon";
 const PROVIDER_ICONS: Record<string, typeof Bot> = {
   claude: ClaudeIcon as unknown as typeof Bot,
   codex: CodexIcon as unknown as typeof Bot,
-  gemini: GeminiIcon as unknown as typeof Bot,
-  amp: AmpIcon as unknown as typeof Bot,
-  aider: AiderIcon as unknown as typeof Bot,
   copilot: CopilotIcon as unknown as typeof Bot,
   opencode: OpenCodeIcon as unknown as typeof Bot,
   pi: PiIcon as unknown as typeof Bot,