feat: add chat modes and interrupt feature (#46)

### Explanation

_No response_

### Issue

Closes #40

### 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

_No response_

Reviewed-on: #46
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/lib/stores/claude.ts

@@ -1,5 +1,6 @@
 import { writable, derived } from "svelte/store";
 import type { ConnectionStatus, PermissionRequest } from "$lib/types/messages";
+import { characterState } from "$lib/stores/character";
 
 export interface TerminalLine {
   id: string;
@@ -18,6 +19,8 @@ function createClaudeStore() {
   const isProcessing = writable<boolean>(false);
   const grantedTools = writable<Set<string>>(new Set());
   const pendingRetryMessage = writable<string | null>(null);
+  const shouldRestoreHistory = writable<boolean>(false);
+  const savedConversationHistory = writable<string | null>(null);
 
   let lineIdCounter = 0;
 
@@ -34,6 +37,8 @@ function createClaudeStore() {
     isProcessing: { subscribe: isProcessing.subscribe },
     grantedTools: { subscribe: grantedTools.subscribe },
     pendingRetryMessage: { subscribe: pendingRetryMessage.subscribe },
+    shouldRestoreHistory: { subscribe: shouldRestoreHistory.subscribe },
+    savedConversationHistory: { subscribe: savedConversationHistory.subscribe },
 
     setConnectionStatus: (status: ConnectionStatus) => connectionStatus.set(status),
     setSessionId: (id: string | null) => sessionId.set(id),
@@ -106,6 +111,21 @@ function createClaudeStore() {
 
     setPendingRetryMessage: (message: string | null) => pendingRetryMessage.set(message),
 
+    setShouldRestoreHistory: (should: boolean) => shouldRestoreHistory.set(should),
+    setSavedConversationHistory: (history: string | null) => savedConversationHistory.set(history),
+
+    getShouldRestoreHistory: (): boolean => {
+      let should = false;
+      shouldRestoreHistory.subscribe((s) => (should = s))();
+      return should;
+    },
+
+    getSavedConversationHistory: (): string | null => {
+      let history: string | null = null;
+      savedConversationHistory.subscribe((h) => (history = h))();
+      return history;
+    },
+
     reset: () => {
       connectionStatus.set("disconnected");
       sessionId.set(null);
@@ -115,6 +135,8 @@ function createClaudeStore() {
       isProcessing.set(false);
       grantedTools.set(new Set());
       pendingRetryMessage.set(null);
+      shouldRestoreHistory.set(false);
+      savedConversationHistory.set(null);
     },
   };
 }
@@ -125,3 +147,15 @@ export const hasPermissionPending = derived(
   claudeStore.pendingPermission,
   ($permission) => $permission !== null
 );
+
+// Derived store to check if Claude is currently processing (can be interrupted)
+export const isClaudeProcessing = derived(
+  [claudeStore.connectionStatus, characterState],
+  ([$connectionStatus, $characterState]) => {
+    // Must be connected and in one of the processing states
+    return (
+      $connectionStatus === "connected" &&
+      ["thinking", "typing", "searching", "coding", "mcp"].includes($characterState)
+    );
+  }
+);

src/lib/stores/historyRestore.ts

@@ -0,0 +1,29 @@
+// Separate module for history restoration to ensure persistence across reconnects
+let shouldRestore = false;
+let savedHistory: string | null = null;
+
+export function setShouldRestoreHistory(should: boolean) {
+  shouldRestore = should;
+  console.log("Setting shouldRestoreHistory to:", should);
+}
+
+export function setSavedHistory(history: string | null) {
+  savedHistory = history;
+  console.log("Setting savedHistory, length:", history?.length || 0);
+}
+
+export function getShouldRestoreHistory(): boolean {
+  console.log("Getting shouldRestoreHistory:", shouldRestore);
+  return shouldRestore;
+}
+
+export function getSavedHistory(): string | null {
+  console.log("Getting savedHistory, length:", savedHistory?.length || 0);
+  return savedHistory;
+}
+
+export function clearHistoryRestore() {
+  console.log("Clearing history restore flags");
+  shouldRestore = false;
+  savedHistory = null;
+}

src/lib/stores/messageMode.ts

@@ -0,0 +1,20 @@
+import { writable } from "svelte/store";
+
+// Default to chat mode
+const messageModeStore = writable<string>("chat");
+
+export const messageMode = {
+  subscribe: messageModeStore.subscribe,
+  set: (mode: string) => {
+    console.log("Setting message mode to:", mode);
+    messageModeStore.set(mode);
+  },
+  reset: () => messageModeStore.set("chat"),
+};
+
+// Helper to get current mode
+export function getCurrentMode(): string {
+  let currentMode = "chat";
+  messageMode.subscribe((mode) => (currentMode = mode))();
+  return currentMode;
+}