fix: #4749 handle malformed percent-encoded local links - #4773

Upstream PRs applied (all diff-reviewed, tests included and passing):
- marktext#4776: preserve ordered-list source markers — opening and saving no
  longer rewrites 1./1./1. to 1./2./3. (marktext#4772, silent doc mutation)
- marktext#4788: UNC/WSL paths become valid file:// authority URLs
  (file://server/share/…, not file:////…) so network images load
  (marktext#4577, marktext#4563)
- marktext#4952: table columns size to content (min-width 10em → 2em, marktext#4894)
- marktext#4773: malformed percent-escape in a clicked link no longer throws an
  unhandled URIError (marktext#4749)
- marktext#4873: Shift+digit/punctuation keybindings recordable and matchable
  again (patch-package fix for @hfelix/electron-localshortcut, marktext#4863)
- marktext#4910: sidebar icons match by extension first, so Dockerfile-Notes.md
  gets the markdown icon (marktext#4890)
- marktext#4317: restored windows are clamped to the target display's work area
  (multi-monitor / DPI, marktext#2928, marktext#1947)

Found while integrating marktext#4776: cloneStateTree shallow-copied meta, so
array-valued fields (order-list sourceMarkers, table aligns) stayed
SHARED between a getState() clone and the live document — mutating a
returned tree corrupted the document. Meta arrays are now copied, and
the clone walks an explicit work list instead of recursing, so
pathological nesting (600-level lists, marktext#4747) can no longer overflow
the call stack (10k-depth regression test).

Also: folder search debounces its per-keystroke ripgrep run (300ms,
Enter searches immediately, IME-composing keys ignored) (marktext#3556), and a
new undoFloor spec pins that undoing past the opened baseline never
empties the document (marktext#5028 — legacy-engine bug, does not reproduce on
@muyajs/core).

muya 1536/1536, desktop 783/783, lint/tsc/madge clean. PLANS.md gains a
prioritized backlog from the full 563-item issue/PR survey.

…folder (#5506)

`resolveLocalLinkTarget` joined the document folder with the link target and
then percent-decoded the joined string, unguarded. The target is URL-encoded
text taken from the document, but `dirname` is a raw filesystem path that may
legally contain `%`, so decoding the join misread the document's own folder
name: a folder called `50%off` made every ordinary link inside it throw
`URIError` out of the `mt::format-link-click` handler, and one called
`my%20docs` resolved to `my docs`. Decode the target alone and join the raw
dirname — the mirror of `encodeDirnameForUrl` on the renderer side (#5212).
`isAbsolute` keeps testing the encoded target so a `%2F` cannot turn a relative
link into an absolute one.

A target that is not valid percent-encoding threw as well: `bad%zz.md`, `%.md`,
`%E0%A4%A.md`, and also `other.md#100%`, since `toPathname` runs before the `#`
split. `%` is a legal filename character, so fall back to the target as written,
the same guard the renderer already applies in `SCROLL_TO_ANCHOR`. Keeping it
inside `toPathname` is what lets the fragment case resolve: the literal path
does not exist, so the `#` split runs and `other.md` opens with `100%` handed to
the renderer, which tolerates an undecodable anchor.

Since #5298 made this handler `async` the throw surfaced as an unhandled
rejection rather than the error dialog reported in #4749, so the symptom on
develop was a click that did nothing at all.

A click on a target that does not exist stays a no-op, as it already is for any
other broken local link.

Closes #4749
Supersedes #4773

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>