chore(ui): refactor workspace to monorepo (#70)

## Summary by Sourcery

Refactor the UI project structure into a pnpm monorepo packages layout
and align tooling and automation with the new paths.

Enhancements:
- Reorganize the UI app from the root ui directory into packages/ui
within a pnpm workspace.
- Update pnpm workspace configuration to include all packages under
packages/*.
- Adjust paths in changeset configuration so the @dropout/ui package
resolves from packages/ui.

Build:
- Update pre-commit configuration paths and arguments to reflect the new
UI location and normalize hook argument formatting.
- Update Dependabot configuration so npm updates target /packages/ui
instead of /ui.

CI:
- Update GitHub Actions workflows to watch packages/** instead of ui/**
and to run frontend tasks from packages/ui.
- Update pnpm cache dependency paths in workflows to use the root
pnpm-lock.yaml.
- Simplify frontend install steps in test workflows to run from the
repository root.

Chores:
- Add a new index.html under packages/ui and remove the old
ui/index.html to match the new project layout.

1 files changed, 0 insertions, 166 deletions

diff --git a/ui/src/stores/assistant.svelte.ts b/ui/src/stores/assistant.svelte.ts
deleted file mode 100644
index a3f47ea..0000000
--- a/ui/src/stores/assistant.svelte.ts
+++ /dev/null
@@ -1,166 +0,0 @@
-import { invoke } from "@tauri-apps/api/core";
-import { listen, type UnlistenFn } from "@tauri-apps/api/event";
-
-export interface GenerationStats {
-  total_duration: number;
-  load_duration: number;
-  prompt_eval_count: number;
-  prompt_eval_duration: number;
-  eval_count: number;
-  eval_duration: number;
-}
-
-export interface Message {
-  role: "user" | "assistant" | "system";
-  content: string;
-  stats?: GenerationStats;
-}
-
-interface StreamChunk {
-  content: string;
-  done: boolean;
-  stats?: GenerationStats;
-}
-
-// Module-level state using $state
-let messages = $state<Message[]>([]);
-let isProcessing = $state(false);
-let isProviderHealthy = $state(false);
-let streamingContent = "";
-let initialized = false;
-let streamUnlisten: UnlistenFn | null = null;
-
-async function init() {
-  if (initialized) return;
-  initialized = true;
-  await checkHealth();
-}
-
-async function checkHealth() {
-  try {
-    isProviderHealthy = await invoke("assistant_check_health");
-  } catch (e) {
-    console.error("Failed to check provider health:", e);
-    isProviderHealthy = false;
-  }
-}
-
-function finishStreaming() {
-  isProcessing = false;
-  streamingContent = "";
-  if (streamUnlisten) {
-    streamUnlisten();
-    streamUnlisten = null;
-  }
-}
-
-async function sendMessage(
-  content: string,
-  isEnabled: boolean,
-  provider: string,
-  endpoint: string,
-) {
-  if (!content.trim()) return;
-  if (!isEnabled) {
-    messages = [
-      ...messages,
-      {
-        role: "assistant",
-        content: "Assistant is disabled. Enable it in Settings > AI Assistant.",
-      },
-    ];
-    return;
-  }
-
-  // Add user message
-  messages = [...messages, { role: "user", content }];
-  isProcessing = true;
-  streamingContent = "";
-
-  // Add empty assistant message for streaming
-  messages = [...messages, { role: "assistant", content: "" }];
-
-  try {
-    // Set up stream listener
-    streamUnlisten = await listen<StreamChunk>("assistant-stream", (event) => {
-      const chunk = event.payload;
-
-      if (chunk.content) {
-        streamingContent += chunk.content;
-        // Update the last message (assistant's response)
-        const lastIdx = messages.length - 1;
-        if (lastIdx >= 0 && messages[lastIdx].role === "assistant") {
-          messages[lastIdx] = {
-            ...messages[lastIdx],
-            content: streamingContent,
-          };
-          // Trigger reactivity
-          messages = [...messages];
-        }
-      }
-
-      if (chunk.done) {
-        if (chunk.stats) {
-          const lastIdx = messages.length - 1;
-          if (lastIdx >= 0 && messages[lastIdx].role === "assistant") {
-            messages[lastIdx] = {
-              ...messages[lastIdx],
-              stats: chunk.stats,
-            };
-            messages = [...messages];
-          }
-        }
-        finishStreaming();
-      }
-    });
-
-    // Start streaming chat
-    await invoke<string>("assistant_chat_stream", {
-      messages: messages.slice(0, -1), // Exclude the empty assistant message
-    });
-  } catch (e) {
-    console.error("Failed to send message:", e);
-    const errorMessage = e instanceof Error ? e.message : String(e);
-
-    let helpText = "";
-    if (provider === "ollama") {
-      helpText = `\n\nPlease ensure Ollama is running at ${endpoint}.`;
-    } else if (provider === "openai") {
-      helpText = "\n\nPlease check your OpenAI API key in Settings.";
-    }
-
-    // Update the last message with error
-    const lastIdx = messages.length - 1;
-    if (lastIdx >= 0 && messages[lastIdx].role === "assistant") {
-      messages[lastIdx] = {
-        role: "assistant",
-        content: `Error: ${errorMessage}${helpText}`,
-      };
-      messages = [...messages];
-    }
-
-    finishStreaming();
-  }
-}
-
-function clearHistory() {
-  messages = [];
-  streamingContent = "";
-}
-
-// Export as an object with getters for reactive access
-export const assistantState = {
-  get messages() {
-    return messages;
-  },
-  get isProcessing() {
-    return isProcessing;
-  },
-  get isProviderHealthy() {
-    return isProviderHealthy;
-  },
-  init,
-  checkHealth,
-  sendMessage,
-  clearHistory,
-};