fix: podtui binary crashed with 'preload not found' when launched from repo root

The embedded runtime reads the CWD bunfig.toml at startup; the repo's
top-level 'preload = ["@opentui/solid/preload"]' made the standalone die
because that module isn't bundled. Removed the ambient preload from
bunfig.toml and moved the solid transform registration to explicit
--preload flags in the start/dev scripts ([test] preload untouched).

Verified: binary boots from repo root, from a clean dir, and dev/start
still work; bun test 54 pass. No new release needed — the binaries were
never config-dependent; this was purely the repo's bunfig trap.

package.json

@@ -8,8 +8,8 @@
     "podtui": "./dist/index.js"
   },
   "scripts": {
-    "start": "bun src/index.tsx",
-    "dev": "bun --watch src/index.tsx",
+    "start": "bun --preload @opentui/solid/preload src/index.tsx",
+    "dev": "bun --preload @opentui/solid/preload --watch src/index.tsx",
     "build:native": "bash scripts/build-cavacore.sh",
     "build": "bun run build.ts",
     "dist": "bun dist/index.js",