v1.7.2 — reject corrupt zstd frames; preserve content and client lifecycle

A Export MD button in the DSH Web session header that writes the current
conversation to a file chosen through the native save dialog, plus a CLI and an
HTTP route over the same renderer. A toast then names the file that was written, or
carries the reason if it failed.

It reads session logs directly from disk, multi-frame zstd included, and handles
v0, v3 and v4 — each verified against real logs.

Requires Node 22.15+. The node:zlib zstd API does not exist in Node 20 or 21.

After installing or updating, restart DSH and hard-refresh the page
(⌘⇧R / Ctrl+Shift+R).

Install

Open Plugins in the DSH sidebar → Add plugin → paste
https://github.com/hoshF/dsh-md-export → restart DSH.

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Fixed

• Reject corrupt or truncated zstd frames and trailing garbage instead of silently
  skipping content; validate complete frame boundaries and the decoder's input
  consumption.
• Preserve consecutive blank lines in message code blocks and tool arguments/results.
• Keep Unicode surrogate pairs intact when truncating title-based filenames.
• Exclude sentence punctuation from bare references and number mixed bare/Markdown
  links by their actual first appearance, retaining labelled duplicates.
• Cancel stale saved-state timers and prevent overlapping exports or UI updates
  after unmount; cancellation and failures allow retrying.
• Reject missing CLI output paths before writing files, and list all sessions
  instead of silently stopping at 40.
• Remove misleading pre-v3 warnings from the CLI and manual smoke script. Earlier
  changelog statements that these warnings never existed have been corrected.

Added

• Compression integrity, content-preservation, Unicode filename, reference,
  client lifecycle and CLI regression tests; all test/*.test.mjs files run in CI.

Documentation

• Synchronise both READMEs and the format contract with strict frame decoding,
  filename refresh timing, whitespace preservation and CLI argument handling.