fix(core): handle read file failures

[kitlangton]

Summary

• keep filesystem races during read, inspect, and directory listing in the typed error channel
• model binary, oversized media, malformed UTF-8, wrong path kinds, and invalid offsets with Schema.TaggedErrorClass
• preserve useful content-error messages while allowing the read tool to settle failures for the model
• decode paginated files one newline-bounded segment at a time and stop as soon as the requested page is complete
• keep arbitrary defects and interruption outside the recovery boundary

Closes #33068

Test plan

• bun run test test/tool-read-filesystem.test.ts test/tool-read.test.ts from packages/core (24 passed)
• regressions cover malformed UTF-8 in later chunks and ignored malformed/NUL content after a completed page
• bun typecheck from packages/core
• pre-push bun turbo typecheck (23 packages passed)
• Prettier and git diff --check