fix(quarto-parse-errors): point Q-2-12 'opening *' note at the delimiter (bd-1lpkx)

[cscheid]

Summary

For an unclosed single-star emphasis, the This is the opening '*' mark. diagnostic detail underlined the word preceding the * instead of the * itself (off by len(preceding word)):

 1 │ hello world *baz
   │       ──┬──     ┬
   │         ╰──────── This is the opening '*' mark.   ← points at "world"

Root cause

A corpus-data bug, not the matcher. The error machinery records, per capture, the (lr_state, sym) of the tree-sitter token at the capture's (row, column, size) in the example, then resolves it at runtime via find_matching_token.

Q-2-12.json's simple case (content "a *") placed the emphasis-start capture at column 0 — the a text run — so the generated table recorded pandoc_str_token1 for every simple-N variant, and the runtime matcher walked back to the most recent text run (the preceding word).

Fix

Move the capture to column 1, size 2 — the " *" emphasis_delimiter token (the note already sets trimLeadingSpace/trimTrailingSpace, collapsing the span onto the *). This mirrors the already-correct stray-ending-star case.

Regenerated _autogen-table.json: all 32 Q-2-12 captures now record emphasis_delimiter (0 pandoc_str_token1). The regeneration diff is Q-2-12-only; no snapshot or case-file churn.

Scope (narrower than first assumed)

Verified end-to-end that Q-2-13 (**) and Q-2-5 (_) already point their opening notes at the delimiter in the simple case — no change needed.

Tests

Adds test_emphasis_opening_mark (drives the real pampa::readers::qmd::read path):

• hello world *baz → opening detail at byte 12 (the *)
• foo *bar → byte 4

Failed pre-fix at byte 6 (start of "world"); passes post-fix.

Verification

• cargo nextest run -p pampa — 3776 passed
• cargo nextest run --workspace — 9484 passed
• cargo xtask verify --skip-hub-build — all steps passed
• Regression test re-run green on this branch against current main
• End-to-end via the binary: the caret now underlines the *

🤖 Generated with Claude Code