pi-image-paths: attach dropped image paths and draw them in the chat

A screenshot is normally sent to pi as a path, so the model gets its text and
the reader gets nothing: pi renders image blocks in tool results but never on
user messages. This extension closes both halves — the path collapses to
"[Image #N]" as you type or on send, and the picture is drawn below the sent
message.

The rewrite is a terminal-input listener that re-reads a settled editor, joins
word by word for paths with unescaped spaces, and reports a path that does not
exist instead of eating the prompt. The drawing appends a custom session entry
carrying the message's image blocks, one macrotask after message_end so it lands
below the message pi persists afterwards, and renders it with pi-tui's inline
image component under terminal.showImages and terminal.imageWidthCells. Entries
stay out of the model context, so each image is still sent to the model once.

Tests: npm test (21, node:test over a stand-in for pi: rewrite, send-time
attachment, missing paths, append gate, renderer gating) and npm run typecheck.

Co-Authored-By: nw-flash-flex <noreply@freno.me>

tsconfig.json

@@ -0,0 +1,29 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "noEmit": true,
+    "skipLibCheck": true,
+    "paths": {
+      "@earendil-works/pi-coding-agent": [
+        "/opt/homebrew/lib/node_modules/@earendil-works/pi-coding-agent/dist/index.d.ts"
+      ],
+      "@earendil-works/pi-agent-core": [
+        "/opt/homebrew/lib/node_modules/@earendil-works/pi-coding-agent/node_modules/@earendil-works/pi-agent-core/dist/index.d.ts"
+      ],
+      "@earendil-works/pi-ai": [
+        "/opt/homebrew/lib/node_modules/@earendil-works/pi-coding-agent/node_modules/@earendil-works/pi-ai/dist/index.d.ts"
+      ],
+      "@earendil-works/pi-tui": [
+        "/opt/homebrew/lib/node_modules/@earendil-works/pi-coding-agent/node_modules/@earendil-works/pi-tui/dist/index.d.ts"
+      ],
+      "typebox": [
+        "/opt/homebrew/lib/node_modules/@earendil-works/pi-coding-agent/node_modules/typebox"
+      ]
+    },
+    "baseUrl": "."
+  },
+  "include": ["*.ts"]
+}