fix(review): bound E2B readBytes at the seam, prove conditional-registration disposal, and align read_image contracts

- E2BFileSystem.readBytes now short-circuits on the stat size before any
  content transfer and streams the remote object, cancelling at the first
  chunk past the cap, honoring the seam's bounded-buffering contract; the
  fs-e2b README pair documents the new primitive.
- The tool-fs HMR test now proves the attachments-scoped registration:
  disposing the store withdraws read_image while read/write/edit stay,
  remounting restores it, and disposing the plugin withdraws everything.
- read_image caps reads at the smaller of maxImageBytes and
  maxMessageImageBytes, records an absent observation for a missing
  target like its sibling read, widens the mismatch remedy to cover
  out-of-family formats, and renames the gate's parameter to
  requestedPath; module/apply/registration JSDoc now match the shipped
  composition. zh terminology aligned; the examples manifest keeps its
  literal arrow.

examples/package.json

@@ -3,7 +3,7 @@
   "private": true,
   "version": "0.0.1",
   "type": "module",
-  "description": "Workspace umbrella for runnable demos and example-owned test compositions: declares their cordis.yml packages so plain Node resolves real exports\u2192lib. Not a build target.",
+  "description": "Workspace umbrella for runnable demos and example-owned test compositions: declares their cordis.yml packages so plain Node resolves real exports→lib. Not a build target.",
   "dependencies": {
     "@cordisjs/plugin-hmr": "workspace:*",
     "@cordisjs/plugin-include": "workspace:*",