P1: typed RPC bridge + FileSystemProvider + dual-panel local browsing

- shared/types + shared/rpc: full wire contract (Result envelope, no exceptions cross the bridge)
- FileSystemProvider interface, LocalProvider, SessionRegistry with built-in 'local'
- walk.ts: provider-generic recursive walk + removeRecursive
- rpc-handlers wired into BrowserWindow; 10min request timeout for slow SFTP ops
- Angular: RpcService (Electroview bridge + plain-browser guard), PanelsService with
  signals-based PanelState (sort/cursor/selection), FilePanel component with
  keyboard nav (arrows/Space/Enter/Backspace/Tab), path bar, toasts
- verified: both panels listDir home over the bridge in the running app

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/shared/types.ts

@@ -0,0 +1,68 @@
+export type EntryType = "file" | "dir" | "symlink";
+
+export interface FileEntry {
+	name: string;
+	path: string; // absolute path on its filesystem
+	type: EntryType;
+	size: number; // bytes
+	mtime: number; // epoch milliseconds
+	mode: number; // permission bits only (masked & 0o7777)
+}
+
+/** Every RPC response uses this envelope; errors never cross the bridge as exceptions. */
+export type Result<T = object> = ({ ok: true } & T) | { ok: false; error: string };
+
+export type AuthConfig =
+	| { kind: "password"; password: string }
+	| { kind: "key"; privateKeyPath: string; passphrase?: string };
+
+export interface ConnectionConfig {
+	host: string;
+	port: number;
+	username: string;
+	auth: AuthConfig;
+	initialPath?: string | null;
+}
+
+export interface SavedConnection extends ConnectionConfig {
+	id: string;
+	folderId: string | null;
+	name: string;
+}
+
+export interface ConnFolder {
+	id: string;
+	name: string;
+}
+
+export interface ConnectionsFile {
+	version: 1;
+	folders: ConnFolder[];
+	connections: SavedConnection[];
+}
+
+export type TransferState =
+	| "queued"
+	| "scanning"
+	| "running"
+	| "completed"
+	| "failed"
+	| "cancelled";
+
+export interface TransferSnapshot {
+	id: string;
+	name: string; // display name (basename of source)
+	srcSessionId: string;
+	srcPath: string;
+	dstSessionId: string;
+	dstDir: string;
+	state: TransferState;
+	totalFiles: number;
+	totalBytes: number;
+	doneFiles: number;
+	doneBytes: number;
+	currentFile: string;
+	currentFileBytes: number;
+	currentFileTotal: number;
+	error?: string;
+}