Feat/auto markdown links tags

[Floper]

Markdown export: links, tags, OCR markup, auto-sync and mirror folder

This PR builds on the updated supernote-typescript submodule (which now parses
internal links and keyword stars) to surface those features as Obsidian-native
constructs in the exported markdown. It also fixes several bugs in the auto-sync
workflow and adds new settings to control the behaviour.

Supernote keywords → Obsidian tags

Starred keywords from the Supernote app are emitted as Obsidian tags (e.g.
#Supernote_Keyword) on the correct page of the exported markdown, rather than
as a flat list at the top of the document.

• The source page is derived from the KEYWORD footer key prefix (first 4 digits,
  1-indexed), matching the LINKO key format. This is more reliable than the
  KEYWORDPAGE field, which can be '0' (invalid).
• Tags are emitted before the OCR text on each page but deduplicated: if the
  same tag was already embedded in the processed OCR text (see below), it is not
  repeated in the page header.
• A note-level keyword map is built at export time so that brand-new tags — not
  yet indexed in the Obsidian vault — are still recognised as tags rather than
  headings during OCR processing.

Supernote links → Wikilinks

Internal links created via the Supernote link feature are emitted as Obsidian
Wikilinks on the correct page.

• The source page is derived from the LINKO footer key prefix (first 4 digits,
  1-indexed) rather than OBJPAGE, which is unreliable.
• Links within a page are ordered top-to-bottom by sorting LINKO keys
  (the key encodes the Y coordinate after the page prefix).
• Page anchors: for same-document links the text field already contains
  #Page N (resolved by the library). For cross-file links the plugin loads the
  target .note from the vault, parses it, and resolves the PAGEID to a page
  number — e.g. [[other-note#Page 2]]. A per-call cache avoids re-parsing the
  same file multiple times.
• Links with PAGEID: 'none' or where the target file is not in the vault
  produce a plain Wikilink without a page anchor.

OCR markup: # → tags/headings, @ → Wikilinks

A new processHashtagsAndMentions function post-processes the OCR text of each
page:

• #Word or # Word: checked against the Obsidian vault tag index. If the tag
  exists → inline tag (#Word); otherwise → Markdown heading (# Word). Two-word
  combinations (e.g. # Existing Tag) are also checked as #existing_tag before
  falling back to a heading. The note's own keyword stars are checked first so
  newly created tags are recognised even before they appear in the vault index.
• @ Word(s): everything after the @ on the same line becomes a Wikilink
  ([[Word(s)]]), supporting multi-word note names.

Auto-sync fixes

• Path construction bug: the previous code used
  `${file.parent?.path}/${file.basename}.md` which produces //name.md for
  vault-root files (Obsidian returns "/" as the root folder path). The output
  path is now derived from file.path.replace(/\.note$/i, '.md'), which Obsidian
  always formats correctly.
• Race condition: when a .note file syncs, Obsidian fires both 'create'
  and 'modify' events in quick succession. Both handlers called
  vault.create, causing a "File already exists" error. The overwrite path
  now wraps vault.create in a try/catch and retries with vault.modify when
  the file appeared between the existence check and the create.
• attachMarkdownFile now properly awaits writeMarkdownFile so errors
  surface rather than being silently dropped as unhandled promise rejections.
• .catch() handlers added to both vault event callbacks so any remaining errors
  appear in the developer console instead of as uncaught exceptions.

Markdown mirror folder

A new optional setting lets users save all exported markdown files into a
dedicated vault folder that mirrors the .note file structure, instead of
placing each .md file alongside its .note file.

• Setting: Markdown mirror folder (text input, empty by default = save
  alongside). Example value: SupernoteMarkdowns.
• ensureFolderExists walks the path segment by segment, creating any missing
  intermediate folders (with a concurrent-creation guard).
• Works correctly for notes at the vault root and in nested subfolders.

New settings

All new behaviours are opt-out via toggles in the plugin settings:

Setting	Default	Description
isAutoSyncMarkdownEnabled	false	Auto-export markdown when a .note file changes
isKeywordsAndLinksEnabled	true	Convert keywords to tags and links to Wikilinks
isHashtagsMentionsEnabled	true	Convert # and @ in OCR text
markdownMirrorFolder	""	Output folder for mirrored markdown files