refactor(commit-ai): remove local models and simplify AI flow

Remove local on-device model support and related IPC commands,
consolidating commit-generation to cloud providers and simplifying the
AI crate surface. Local-specific types, generation profiles, caching,
and the local prompt builder were removed while message sanitization and
diff-echo detection were preserved. Also harden repository handling and
runtime: unborn HEADs are handled gracefully so empty repos still report
files, Git LFS sync is skipped for repositories without commits, and
tokio runtime features were enabled.

- Remove local model engine, load/status commands, and local profile code
- Handle unborn HEAD and skip LFS sync for repos without commits
- Enable tokio runtime features and route AI generation to cloud only

src/lib/components/AiSettingsDialog.svelte

@@ -1,20 +1,18 @@
 <script lang="ts">
   import { onDestroy, onMount } from "svelte";
-  import { AlertCircle, Bot, Check, Cpu, Eye, EyeOff, Gauge, Globe, Key, LoaderCircle, Sparkles, X, Zap } from "@lucide/svelte";
+  import { Bot, Check, Eye, EyeOff, Globe, Key, LoaderCircle, X } from "@lucide/svelte";
   import { credDelete, credLoad, credSave } from "../git";
-  import type { AiSettings, CommitAiLocalProfile, CommitAiProvider, LocalModelOption } from "../types";
-  import SelectMenu from "./SelectMenu.svelte";
+  import type { AiSettings, CommitAiProvider } from "../types";
 
   interface Props {
     settings: AiSettings;
-    localModels: LocalModelOption[];
     onSave: (settings: AiSettings) => void;
     onClose: () => void;
   }
 
-  let { settings, localModels = [], onSave, onClose }: Props = $props();
+  let { settings, onSave, onClose }: Props = $props();
 
-  type CloudProvider = Exclude<CommitAiProvider, "local">;
+  type CloudProvider = CommitAiProvider;
 
   const CRED_KEYS: Record<CloudProvider, string> = {
     openai: "ai:openai",
@@ -22,9 +20,7 @@
     custom: "ai:custom",
   };
 
-  let provider = $state<CommitAiProvider>("local");
-  let localModelId = $state("");
-  let localProfile = $state<CommitAiLocalProfile>("fast");
+  let provider = $state<CommitAiProvider>("openai");
   let openaiModel = $state("");
   let anthropicModel = $state("");
   let customBaseUrl = $state("");
@@ -41,8 +37,6 @@
 
   $effect(() => {
     provider = settings.provider;
-    localModelId = settings.localModelId;
-    localProfile = settings.localProfile ?? "fast";
     openaiModel = settings.openaiModel;
     anthropicModel = settings.anthropicModel;
     customBaseUrl = settings.customBaseUrl;
@@ -103,8 +97,6 @@
       ]);
       onSave({
         provider,
-        localModelId,
-        localProfile,
         openaiModel: openaiModel.trim() || "gpt-4o-mini",
         anthropicModel: anthropicModel.trim() || "claude-3-5-haiku-latest",
         customBaseUrl: customBaseUrl.trim(),
@@ -117,26 +109,6 @@
     }
   }
 
-  function formatSize(mb: number): string {
-    return mb >= 1000 ? `${(mb / 1000).toFixed(1)} GB` : `${mb} MB`;
-  }
-
-  function recommendedModelForProfile(profile: CommitAiLocalProfile): string {
-    if (profile === "balanced") return "qwen2.5-1.5b";
-    if (profile === "detailed") return "qwen2.5-3b";
-    return "qwen2.5-0.5b";
-  }
-
-  function selectLocalProfile(profile: CommitAiLocalProfile) {
-    const previousRecommended = recommendedModelForProfile(localProfile);
-    localProfile = profile;
-    const nextRecommended = recommendedModelForProfile(profile);
-    if (!localModelId || localModelId === previousRecommended) {
-      localModelId = nextRecommended;
-    }
-  }
-
-  let selectedLocalModel = $derived(localModels.find((option) => option.id === localModelId));
 </script>
 
 <div
@@ -156,17 +128,6 @@
 
     <form class="ai-settings-form" onsubmit={(e) => { e.preventDefault(); void handleSave(); }}>
       <div class="ai-provider-options" role="radiogroup" aria-label="AI provider">
-        <button
-          type="button"
-          class="ai-provider-option ai-provider-option-local"
-          class:active={provider === "local"}
-          disabled
-          title="Local AI is still in development and not yet available"
-        >
-          <Cpu size={16} aria-hidden="true" />
-          Local AI
-          <span class="ai-provider-badge">In development</span>
-        </button>
         <button type="button" class="ai-provider-option" class:active={provider === "openai"} onclick={() => { provider = "openai"; }}>
           <Bot size={16} aria-hidden="true" />
           OpenAI
@@ -181,38 +142,7 @@
         </button>
       </div>
 
-      {#if provider === "local"}
-        <div class="cred-field">
-          <span class="cred-field-label">Local speed</span>
-          <div class="ai-local-profile-options" role="radiogroup" aria-label="Local AI speed">
-            <button type="button" class="ai-local-profile-option" class:active={localProfile === "fast"} onclick={() => selectLocalProfile("fast")}>
-              <Zap size={15} aria-hidden="true" />
-              Fast
-            </button>
-            <button type="button" class="ai-local-profile-option" class:active={localProfile === "balanced"} onclick={() => selectLocalProfile("balanced")}>
-              <Gauge size={15} aria-hidden="true" />
-              Balanced
-            </button>
-            <button type="button" class="ai-local-profile-option" class:active={localProfile === "detailed"} onclick={() => selectLocalProfile("detailed")}>
-              <Sparkles size={15} aria-hidden="true" />
-              Detailed
-            </button>
-          </div>
-        </div>
-        <label class="cred-field">
-          <span class="cred-field-label">Model</span>
-          <SelectMenu value={localModelId} options={localModels.map((option) => ({ value: option.id, label: `${option.label} - ${formatSize(option.approx_size_mb)}` }))} onChange={(value) => { localModelId = value; }} />
-        </label>
-        <div class="cred-token-hint">
-          <AlertCircle size={13} aria-hidden="true" />
-          <span>
-            Switching downloads the model{selectedLocalModel ? ` (${formatSize(selectedLocalModel.approx_size_mb)})` : ""}
-            in the background — depending on your internet connection this can take several minutes.
-            After that it stays cached locally and loads instantly on the next start.
-            The speed setting only changes Local AI; API providers keep their existing prompt.
-          </span>
-        </div>
-      {:else if provider === "openai"}
+      {#if provider === "openai"}
         <label class="cred-field">
           <span class="cred-field-label">Model</span>
           <input type="text" bind:value={openaiModel} placeholder="gpt-4o-mini" autocomplete="off" spellcheck="false" />