perf: faster plugin updates, half-size first bundle, images from the chat attach on Windows

- Chat view: an attached image's path is pasted on its own after the text
  (promptForPane). claude turns a paste that is only an image path into
  [Image #n], but left a Windows path inside a paste of text as a plain path.
  Other files and @-mentions stay in the text as before.
- Plugin bootstrap: depsHash covers only what npm installs (no release
  version), so a version bump no longer reinstalls runtime deps; the client's
  installed tree is kept while its manifests are unchanged (no npm ci per
  update); the user-side build runs vite only (tsc -b cost ~25 s / ~900 MB);
  clientBuild is recorded only after a build that did not fail, so a failed
  one is retried; npm output goes to runtime/npm-install.log.
- Server: a port held by another program ends with a clear message and exit 1
  instead of an uncaught 'error' stack trace.
- Client: the onboarding wizard is lazy and rendered only before onboarding;
  usePrefersReducedMotion moved to hooks/ so PetSettings no longer pulls the
  Sagi chat/pane stack into the entry chunk (884 KB -> 431 KB, gzip 268 -> 133 KB).

client/src/lib/panePaste.ts

@@ -14,6 +14,9 @@
  * terminal moves the unsent prompt across (`takeRunInput` reads the TUI's
  * input box off the screen and empties it; the chat's draft is pasted back
  * without Enter), so the half-typed text is never left behind on the other side.
+ * Attached images' paths go after the text, each in a paste of its own: `claude`
+ * turns a paste that is only an image's path into `[Image #n]`, but left a
+ * Windows path (`C:\…\drops\…png`) inside a paste of text as a plain path.
  * The Chat view also answers a menu the CLI asks with (`parsePaneMenu` reads
  * it off the screen; `chooseRunOption`/`answerRunMenu` press its digit, the
  * arrows and Enter, or type into its "Type something" row).
@@ -24,7 +27,8 @@
 export type PaneScreen = { rows: string[]; cols: number };
 
 interface Pane {
-  paste: (text: string, submit?: boolean) => void;
+  /** `files`: image paths pasted after `text`, one paste each. */
+  paste: (text: string, submit?: boolean, files?: string[]) => void;
   visible: () => boolean;
   key?: (data: string) => void;
   /** `menuOnly`: null at once unless a row could be a menu's cursor row. */
@@ -62,19 +66,19 @@ function ofLane(runId: string, laneId: number): boolean {
 
 /** Pastes `text` into the pane of `runId` when it is mounted and on screen;
  *  false otherwise (not mounted yet, or hidden). */
-export function pasteToRun(runId: string, text: string): boolean {
+export function pasteToRun(runId: string, text: string, files: string[] = []): boolean {
   const p = panes.get(runId);
   if (!p?.visible()) return false;
-  p.paste(text);
+  p.paste(text, false, files);
   return true;
 }
 
 /** Sends `text` as a message to the pane of `runId`: a paste, then Enter.
  *  False when the pane is not mounted or not attached. */
-export function submitToRun(runId: string, text: string): boolean {
+export function submitToRun(runId: string, text: string, files: string[] = []): boolean {
   const p = panes.get(runId);
   if (!p?.visible()) return false;
-  p.paste(text, true);
+  p.paste(text, true, files);
   return true;
 }