fix: resolve Obsidian plugin-review findings (1.2.1)

[jphan32]

Two warnings from Obsidian's plugin review, and the reason our own gate did not catch either.

The findings

Source	Finding
Source code	Uses document.createElement instead of Obsidian's createEl helpers — obsidianmd/prefer-create-el, src/main.ts:96
CSS lint	Unexpected browser feature "text-decoration" is only partially supported — styles.css:449

Both are real. el() created elements with activeDocument.createElement, and the inert footnote marker's cue used the multi-value text-decoration: underline dotted shorthand.

The fixes

• el() now calls the free createEl(tag, { cls }). Deliberately not Node.createEl — that one appends to the node it is called on, and el() has to return a detached element.
• The dotted underline is written as text-decoration-line + text-decoration-style. Both longhands predate the shorthand's multi-value form by a wide margin.

Why CI was green while both stood

This is the part worth reviewing.

1. eslint-plugin-obsidianmd was pinned at 0.3.0, which does not carry prefer-create-el. The reviewer runs a newer ruleset, so our gate was checking a strictly smaller set of rules than the thing it exists to pre-empt. Bumped to 0.4.1, which reproduces the finding exactly:

   96:16  warning  Use 'activeWindow.createEl(tag)' instead of
                   'activeDocument.createElement(tag)'   obsidianmd/prefer-create-el
   

2. That rule reports at warning severity, and eslint exits 0 on warnings. Even on 0.4.1 the gate would have passed. npm run lint now runs with --max-warnings=0.

Verified the hardened gate bites — reverting el() to activeDocument.createElement fails lint rather than passing with a warning.

Test harness

The e2e bootstrap gained a createEl / Node.prototype.createEl stub written to the real signature (second argument is a class string or a DomElementInfo), not shaped to whatever the bundle happens to call. A stub fitted to the implementation is exactly how a green suite hid a completely broken feature earlier in this release.

Verification

npm run lint            PASS   (--max-warnings=0, plugin 0.4.1)
npm run build           PASS
node --check main.js    PASS
node scripts/validate.mjs   PASS   (versions.json has 1.2.1 → 1.6.6)
npm run test:e2e        PASS   119 checks

Version 1.2.1 — compliance only, no behaviour change.

🤖 Generated with Claude Code