feat: add ability to run multiple agents via tabbed views (#47)

### Explanation

_No response_

### Issue

Closes #30 Closes #41

### Attestations

- [ ] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [ ] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [ ] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

- [ ] I have run the linter and resolved any errors.
- [ ] My pull request uses an appropriate title, matching the conventional commit standards.
- [ ] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

### Documentation

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### Versioning

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Reviewed-on: #47
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/lib/components/ConversationTabs.svelte

@@ -0,0 +1,279 @@
+<script lang="ts">
+  import { claudeStore } from "$lib/stores/claude";
+  import { onMount } from "svelte";
+  import type { Conversation } from "$lib/stores/conversations";
+  import { SvelteMap } from "svelte/reactivity";
+
+  let conversations: Map<string, Conversation> = new Map();
+  let activeConversationId: string | null = null;
+  let editingTabId: string | null = null;
+  let editingName = "";
+
+  // Track which conversation actually has the Claude connection
+  let connectedConversationId: string | null = null;
+
+  // Track last seen message count for each conversation
+  let lastSeenMessageCount = new SvelteMap<string, number>();
+
+  claudeStore.conversations.subscribe((convs) => {
+    conversations = convs;
+
+    // Update the last seen count for the active conversation
+    if (activeConversationId) {
+      const activeConv = convs.get(activeConversationId);
+      if (activeConv) {
+        lastSeenMessageCount.set(activeConversationId, activeConv.terminalLines.length);
+      }
+    }
+  });
+
+  claudeStore.activeConversationId.subscribe((id) => {
+    activeConversationId = id;
+  });
+
+  // Find the connected conversation
+  $: {
+    let foundConnected = false;
+    for (const [id, conv] of conversations) {
+      if (conv.connectionStatus === "connected" || conv.connectionStatus === "connecting") {
+        connectedConversationId = id;
+        foundConnected = true;
+        break;
+      }
+    }
+    if (!foundConnected) {
+      connectedConversationId = null;
+    }
+  }
+
+  function createNewTab() {
+    claudeStore.createConversation();
+  }
+
+  async function switchTab(id: string) {
+    if (editingTabId) {
+      saveTabName();
+    }
+    await claudeStore.switchConversation(id);
+
+    // Mark messages as seen when switching to this tab
+    const conv = conversations.get(id);
+    if (conv) {
+      lastSeenMessageCount.set(id, conv.terminalLines.length);
+      // Trigger reactivity
+      lastSeenMessageCount = lastSeenMessageCount;
+    }
+  }
+
+  function deleteTab(id: string, event: MouseEvent) {
+    event.stopPropagation();
+    if (conversations.size > 1) {
+      claudeStore.deleteConversation(id);
+    }
+  }
+
+  function startEditing(id: string, name: string, event: MouseEvent) {
+    event.stopPropagation();
+    editingTabId = id;
+    editingName = name;
+    // Focus input after DOM update
+    setTimeout(() => {
+      const input = document.querySelector('.tab-item input[type="text"]') as HTMLInputElement;
+      if (input) input.focus();
+    }, 0);
+  }
+
+  function saveTabName() {
+    if (editingTabId && editingName.trim()) {
+      claudeStore.renameConversation(editingTabId, editingName.trim());
+    }
+    editingTabId = null;
+    editingName = "";
+  }
+
+  function getConnectionStatusColor(status: Conversation["connectionStatus"]): string {
+    switch (status) {
+      case "connected":
+        return "bg-green-500";
+      case "connecting":
+        return "bg-yellow-500";
+      case "disconnected":
+        return "bg-red-500";
+      default:
+        return "bg-gray-500";
+    }
+  }
+
+  function hasUnreadMessages(id: string, conversation: Conversation): boolean {
+    if (id === activeConversationId) return false; // Active tab never has unread
+    const lastSeen = lastSeenMessageCount.get(id) || 0;
+    return conversation.terminalLines.length > lastSeen;
+  }
+
+  function handleKeydown(event: KeyboardEvent) {
+    if (event.key === "Enter") {
+      saveTabName();
+    } else if (event.key === "Escape") {
+      editingTabId = null;
+      editingName = "";
+    }
+  }
+
+  function handleTabKeydown(id: string, event: KeyboardEvent) {
+    if (event.key === "Enter" || event.key === " ") {
+      event.preventDefault();
+      switchTab(id);
+    }
+  }
+
+  // Keyboard shortcuts
+  onMount(() => {
+    function handleGlobalKeydown(event: KeyboardEvent) {
+      // Ctrl/Cmd + T: New tab
+      if ((event.ctrlKey || event.metaKey) && event.key === "t") {
+        event.preventDefault();
+        createNewTab();
+      }
+      // Ctrl/Cmd + W: Close current tab
+      else if ((event.ctrlKey || event.metaKey) && event.key === "w") {
+        event.preventDefault();
+        if (activeConversationId && conversations.size > 1) {
+          claudeStore.deleteConversation(activeConversationId);
+        }
+      }
+      // Ctrl/Cmd + Tab: Next tab
+      else if ((event.ctrlKey || event.metaKey) && event.key === "Tab" && !event.shiftKey) {
+        event.preventDefault();
+        const tabs = Array.from(conversations.keys());
+        const currentIndex = tabs.findIndex((id) => id === activeConversationId);
+        if (currentIndex !== -1) {
+          const nextIndex = (currentIndex + 1) % tabs.length;
+          claudeStore.switchConversation(tabs[nextIndex]);
+        }
+      }
+      // Ctrl/Cmd + Shift + Tab: Previous tab
+      else if ((event.ctrlKey || event.metaKey) && event.key === "Tab" && event.shiftKey) {
+        event.preventDefault();
+        const tabs = Array.from(conversations.keys());
+        const currentIndex = tabs.findIndex((id) => id === activeConversationId);
+        if (currentIndex !== -1) {
+          const prevIndex = (currentIndex - 1 + tabs.length) % tabs.length;
+          claudeStore.switchConversation(tabs[prevIndex]);
+        }
+      }
+    }
+
+    window.addEventListener("keydown", handleGlobalKeydown);
+    return () => window.removeEventListener("keydown", handleGlobalKeydown);
+  });
+</script>
+
+<div
+  class="terminal-tabs flex items-center gap-1 px-2 py-1 bg-[var(--bg-secondary)] border-b border-[var(--border-color)]"
+>
+  {#each Array.from(conversations.entries()) as [id, conversation] (id)}
+    <div
+      class="tab-item group relative flex items-center px-3 py-1.5 rounded-t cursor-pointer transition-all
+        {id === activeConversationId
+        ? 'bg-[var(--bg-terminal)] text-[var(--text-primary)] border-t border-l border-r border-[var(--border-color)]'
+        : 'bg-[var(--bg-tertiary)] text-[var(--text-secondary)] hover:bg-[var(--bg-terminal)]/50'}"
+      onclick={() => switchTab(id)}
+      onkeydown={(e) => handleTabKeydown(id, e)}
+      role="tab"
+      tabindex={0}
+      aria-selected={id === activeConversationId}
+    >
+      {#if editingTabId === id}
+        <input
+          type="text"
+          bind:value={editingName}
+          onblur={saveTabName}
+          onkeydown={handleKeydown}
+          onclick={(e) => e.stopPropagation()}
+          class="bg-transparent border-b border-[var(--border-color)] outline-none px-0 py-0 text-sm w-32"
+        />
+      {:else}
+        <div class="flex items-center gap-2">
+          <div
+            class="w-2 h-2 rounded-full {getConnectionStatusColor(conversation.connectionStatus)}"
+            title="Connection: {conversation.connectionStatus}{id !== connectedConversationId &&
+            connectedConversationId
+              ? ' (Another tab is connected)'
+              : ''}"
+          ></div>
+          <span
+            class="text-sm pr-6 max-w-[150px] truncate"
+            ondblclick={(e) => startEditing(id, conversation.name, e)}
+            role="button"
+            tabindex={-1}
+          >
+            {conversation.name}
+          </span>
+          {#if id !== activeConversationId && id === connectedConversationId}
+            <span
+              class="text-xs text-[var(--text-tertiary)]"
+              title="This tab has the Claude connection"
+            >
+              (connected)
+            </span>
+          {/if}
+          {#if hasUnreadMessages(id, conversation)}
+            <div
+              class="absolute -top-1 -right-1 w-2 h-2 rounded-full bg-blue-500 animate-pulse"
+              title="New messages"
+            ></div>
+          {/if}
+        </div>
+      {/if}
+
+      {#if conversations.size > 1}
+        <button
+          onclick={(e) => deleteTab(id, e)}
+          class="absolute right-1 top-1/2 -translate-y-1/2 w-4 h-4 flex items-center justify-center rounded hover:bg-[var(--bg-secondary)] opacity-0 group-hover:opacity-100 transition-opacity"
+          title="Close tab"
+        >
+          <svg
+            class="w-3 h-3"
+            fill="none"
+            stroke="currentColor"
+            viewBox="0 0 24 24"
+            xmlns="http://www.w3.org/2000/svg"
+          >
+            <path
+              stroke-linecap="round"
+              stroke-linejoin="round"
+              stroke-width="2"
+              d="M6 18L18 6M6 6l12 12"
+            />
+          </svg>
+        </button>
+      {/if}
+    </div>
+  {/each}
+
+  <button
+    onclick={createNewTab}
+    class="new-tab-btn flex items-center justify-center w-7 h-7 rounded hover:bg-[var(--bg-tertiary)] text-[var(--text-secondary)] transition-colors"
+    title="New conversation (Ctrl+T)"
+  >
+    <svg
+      class="w-4 h-4"
+      fill="none"
+      stroke="currentColor"
+      viewBox="0 0 24 24"
+      xmlns="http://www.w3.org/2000/svg"
+    >
+      <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v16m8-8H4" />
+    </svg>
+  </button>
+</div>
+
+<style>
+  .terminal-tabs {
+    min-height: 36px;
+  }
+
+  .tab-item {
+    min-width: 100px;
+  }
+</style>