fix(live): wrap shape-of-output bugs from second Bugbot review

Two more Cursor Bugbot findings on commit 11dfad81:

1. `filterByText` short-text returned the wrong sentinel value.
   When the trimmed snippet was shorter than 8 chars, the function
   returned `candidates.slice()` (all candidates). The caller then
   sees `filtered.length > 1` and fires `element_ambiguous` — exactly
   the opposite of the documented short-text fallback ("caller falls
   back to first-match," which corresponds to `filtered.length === 0`).
   So any picker event with a short textContent on a page with multiple
   matching siblings spuriously errored.
   Fix: return `[]` for short text, matching the JSDoc.

2. `endLine` in the wrap output was wrong for multi-line picked elements.
   `wrapperLines.length` counts ARRAY elements, but one element is a
   `\n`-joined multi-line string (originalIndented). The actual
   wrapper-region row count is `wrapperLines.length + (originalLines.length
   - 1)`. Reporting `endLine = startLine + wrapperLines.length` placed
   the boundary inside the wrapper for any multi-line pick, giving
   downstream agents an incorrect range.
   Fix: add the originalLines offset (matching what `insertLine` already
   does after the prior commit).

Test coverage:
- `short --text falls back to first-match instead of erroneously firing
  element_ambiguous` covers fix #1.
- `returns endLine that includes the multi-line original content offset`
  covers fix #2 by wrapping a 5-line <section> in a real HTML file and
  asserting the reported endLine points at the variants-end marker (and
  the next line is </main>, proving no rows were missed).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/skills/impeccable/scripts/live-wrap.mjs

@@ -261,7 +261,12 @@ The agent should insert variant HTML at insertLine.`);
   console.log(JSON.stringify({
     file: path.relative(process.cwd(), targetFile),
     startLine: startLine + 1,       // 1-indexed for the agent
-    endLine: startLine + wrapperLines.length, // 1-indexed
+    // wrapperLines is an array but one element (the original-content slot)
+    // is a `\n`-joined multi-line string, so the actual file-row count is
+    // wrapperLines.length + (originalLines.length - 1). Without the offset,
+    // endLine pointed inside the wrapper for any picked element that
+    // spanned more than one source line.
+    endLine: startLine + wrapperLines.length + (originalLines.length - 1), // 1-indexed
     insertLine: insertLine + 1,     // 1-indexed: where variants go
     commentSyntax: commentSyntax,
     originalLineCount: originalLines.length,
@@ -480,7 +485,12 @@ function findAllElements(lines, query, tag = null) {
  */
 function filterByText(candidates, lines, text) {
   const trimmed = text.replace(/\s+/g, ' ').trim().toLowerCase().slice(0, 80);
-  if (trimmed.length < 8) return candidates.slice();
+  // Too short to disambiguate. Return [] so the caller's `filtered.length
+  // === 0` branch fires (fall back to first-match) — the previous
+  // `candidates.slice()` return forced `filtered.length > 1` and surfaced
+  // a spurious `element_ambiguous` error on every short-text picker event
+  // with multiple candidates.
+  if (trimmed.length < 8) return [];
   const targetSpaced = trimmed;
   const targetCompact = trimmed.replace(/\s+/g, '');