fix: heading-regex tag corruption, live command toggles, adjacent-file collision, stale selection listeners

- HEADING_REGEX now requires a space/EOL after '#' so tag lines
  (#project ...) are no longer misdetected as headings and corrupted.
- Command enable/disable settings now take effect immediately via
  checkCallback/editorCheckCallback instead of requiring a reload.
- New Adjacent File auto-increments (Untitled.md, Untitled 1.md, ...)
  instead of throwing once Untitled.md already exists.
- Selection-change tracking is delegated from document instead of a
  one-time .cm-content scan, so editors opened after startup are covered.

See CHANGELOG.md for details.

CHANGELOG.md

@@ -0,0 +1,50 @@
+# Changelog
+
+All notable changes to this project are documented in this file.
+Format loosely follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
+
+## [Unreleased]
+
+### Fixed
+
+- **Heading toggle corrupted lines starting with a tag (`#tag ...`).** `HEADING_REGEX`
+  (`src/Constants.ts`) matched any run of leading `#` characters as a heading marker,
+  even without a following space. Obsidian tags like `#project meeting notes` were
+  therefore misread as an existing H1, so running *Toggle Heading - H1* on such a
+  line stripped the `#` instead of adding a heading (and running any other heading
+  level inserted a stray heading marker before the tag). The regex now requires the
+  `#` run to be followed by whitespace or end-of-line before it counts as a heading,
+  matching the ATX heading rule already used by *Toggle Heading (strip formatting)*.
+  (`src/Constants.ts`, `src/ToggleHeading.ts`)
+
+- **Command enable/disable toggles in Settings required an Obsidian restart.**
+  `registerCommands()` only ran once in `onload()`, checking `enabledCommands` at
+  registration time. Flipping a toggle in the settings tab saved the new state but
+  had no effect on the already-registered commands until the plugin was reloaded,
+  contradicting the setting's own description ("Disabled commands will not appear
+  in the command palette"). Commands are now always registered and gated through
+  `checkCallback`/`editorCheckCallback`, so palette visibility and hotkeys respond
+  immediately to settings changes. Command IDs are unchanged, so existing hotkey
+  bindings are unaffected. (`src/main.ts`)
+
+- **"New Adjacent File" failed after the first use in a folder.** The command
+  always targeted a literal `Untitled.md`; `vault.create()` throws if that path
+  already exists (very likely, since it's also Obsidian's own default new-note
+  name), surfacing a raw error `Notice` on every subsequent use. It now finds the
+  next available `Untitled N.md` name in the folder, mirroring Obsidian's built-in
+  new-note behavior. (`src/FileHelper.ts`)
+
+- **Selection-tracking listeners went stale for editors opened after startup.**
+  `registerSelectionChangeListeners()` attached `keydown`/`click`/`dblclick`
+  listeners to every `.cm-content` element found via a single `querySelectorAll`
+  at layout-ready. Editors created afterward (new panes, splits, tabs) got their
+  own `.cm-content` element that was never instrumented, silently degrading the
+  manual-vs-programmatic selection heuristic used by *Select Next/Previous
+  Occurrence*. Listeners are now delegated from `document` in the capture phase,
+  so any editor present now or opened later is covered. (`src/main.ts`)
+
+### Chore
+
+- Reinstalled `node_modules` to pull the `@esbuild/win32-x64` binary; the checked
+  in lockfile/install had resolved only `@esbuild/linux-x64`, so `npm run build`
+  and `npm run dev` failed outright on this machine.