sqlite: reject reentry into a running statement

[TrevorBurnham]

Fixes: #65102

SQLite forbids stepping, resetting, or finalizing a statement while that statement's own user-defined function callback is on the stack. The callback depth added in 5cef767 (#64743) is tracked per database, so it cannot distinguish reentry into the running statement from the common pattern of querying a different statement from a callback.

This adds a per-statement flag, set for the duration of an execution, and rejects step/reset/finalize on that statement with ERR_INVALID_STATE: statement is currently being executed. Before this change:

// silently consumed rows from the iteration in progress
let iter;
db.function('reenter', () => { iter.next(); return 0; });
iter = db.prepare('SELECT reenter() FROM t').iterate();
iter.next();

// failed with "Maximum call stack size exceeded" rather than reporting the constraint
let stmt;
db.function('x', () => stmt.get());
stmt = db.prepare('SELECT x()');
stmt.get();

Covered entry points: all(), get(), run(), iterate(), iterator.next(), iterator.return(), close(), [Symbol.dispose](), and the four SQL tag store methods. close() and [Symbol.dispose]() are included because finalizing mid-step frees the virtual machine that sqlite3_step() is still executing.

Statements other than the running one are unaffected, so the lookup pattern and nested iteration over a different statement keep working — both are covered by tests.

The flag is set before parameter binding, since a getter on a named-parameters object can also reenter.

Prior art: #63183 took this approach alongside its own database-level guard. That PR was closed once #64743 landed, so this salvages the per-statement half and builds on the guard already in main.

Verified locally on macOS arm64: the new test file plus all 20 parallel/test-sqlite* tests pass, including the existing test-sqlite-udf-close.js.

Assisted-by: claude:opus-5

[nodejs-github-bot]

Review requested:

• @nodejs/sqlite

[codecov]

Codecov Report

❌ Patch coverage is 88.46154% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.29%. Comparing base (e2d7b34) to head (02e92f5).
⚠️ Report is 18 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_sqlite.cc	86.36%	0 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #65106      +/-   ##
==========================================
- Coverage   90.31%   90.29%   -0.02%     
==========================================
  Files         759      759              
  Lines      248290   248320      +30     
  Branches    46859    46871      +12     
==========================================
- Hits       224241   224228      -13     
- Misses      15472    15522      +50     
+ Partials     8577     8570       -7     

Files with missing lines	Coverage Δ
src/node_sqlite.h	83.56% <100.00%> (+0.95%)	⬆️
src/node_sqlite.cc	81.15% <86.36%> (+0.09%)	⬆️

... and 36 files with indirect coverage changes

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[TrevorBurnham]

@trivikr I've addressed the issues you noted. The format-cpp check is now timing out after 15 minutes ("The operation was canceled"); the same check succeeds locally.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/75659/