* fix(mobile): truncate oversize markdown reads instead of failing them
The desktop bridge refused markdown over a private 512 KiB cap with
file_too_large, which reached the phone as a generic runtime_error that
the reader discarded, so a 632 KB file showed "Couldn't load markdown".
Reads now return a UTF-8-boundary prefix under one shared 2 MiB budget,
marked truncated with the full byteLength and read-only. The phone shows
the truncation like file tabs do and maps refusal codes to real copy, so
an older desktop's refusal reads "File too large for mobile preview".
Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb
* test(mobile): pin that a truncated markdown read is never editable
The read budget sits above the edit budget, so every truncated document is
already read-only as file_too_large. Pin that ordering so a future budget
change cannot make a prefix editable, and name the constant as the markdown
preview budget, separate from the file preview's own.
Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb
* test(mobile): refuse saves from a truncated markdown read
A phone holding a truncated prefix must not write it back; the 256 KiB
save guard refuses it as file_too_large before any version check. The
shared budget test shrinks to the ordering it pins and names the bridge
test as the behavioural pin.
Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb
* refactor(mobile): tighten markdown truncation types and measure once
The read truncation measures the document once. The disk fallback drops
its truncated-only read-only text, which the status line never showed,
and both truncation fields are optional there. A markdown doc's flag is
only ever true, and the schema comment names the hook, not line numbers.
Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb
* docs(mobile): drop a stale disk-fallback comment
Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb
* chore: retrigger CI after #23675 landed on main
Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb
Jinwoo Hong