[BUG-P0] dashboard_engine.py:655 f-string backslash breaks dashboard command on Python 3.11 (CI runtime)

[Wolfvin]

Summary

scripts/dashboard_engine.py:655 contains a backslash inside an f-string expression part ({...}), which is a SyntaxError on Python 3.11 and earlier. This silently breaks the dashboard command on Python 3.11 (CI's quality-gate (3.11) runtime).

Root cause

Line 655:

{"<button onclick=\"showSection('compare')\">Compare</button>" if comparison else ""}

The \" inside the {...} expression is the backslash. Python 3.11 disallows backslashes in f-string expression parts. Python 3.12 (PEP 701) relaxed this rule, so the file imports fine on 3.12 but fails on 3.11.

Evidence

CI log from PR #71 quality-gate (3.11) job:

[codelens] ERROR: Failed to import command module 'dashboard.py': f-string expression part cannot include a backslash (dashboard_engine.py, line 1331)

Python 3.11 reports the error at line 1331 (the closing triple-quote of the f-string), but the actual backslash is at line 655.

Local repro:

uv run --python 3.11 python3 -c "import dashboard_engine"
# SyntaxError: f-string expression part cannot include a backslash

Impact

1. dashboard command broken on Python 3.11 — module fails to import, auto-import catches the exception silently (see [BUG-09] Command auto-import silently drops broken modules — registry missing commands with no CI signal #39), command missing from registry.
2. CI quality-gate workflow red for ALL PRs — blocks merge of unrelated PRs (fix: consolidate _default_db_path to utils.py — closes #40 #71, feat: rule-validate + rule-test commands — closes #51 #72, etc.).
3. Python 3.11 users cannot use codelens dashboard.

Fix

Replace the backslash-escaped quotes with a triple-quoted string inside the expression (no backslash needed). The current line 655 uses escaped double-quotes inside the f-string expression; swap to single-quote triple-quoted string inside the expression to avoid the backslash entirely.

Using single-quote triple-quoted string inside the double-quote triple-quoted f-string body avoids both the backslash and the delimiter conflict.

Acceptance criteria

• uv run --python 3.11 python3 -c "import dashboard_engine" succeeds
• codelens dashboard appears in codelens --help on Python 3.11
• CI quality-gate (3.11) passes on fix PR
• CI quality-gate (3.11) passes on PR fix: consolidate _default_db_path to utils.py — closes #40 #71 and feat: rule-validate + rule-test commands — closes #51 #72 after fix merges

Related

• Issue [BUG-09] Command auto-import silently drops broken modules — registry missing commands with no CI signal #39 (BUG-09: command auto-import silent drop) — this bug is exactly the scenario [BUG-09] Command auto-import silently drops broken modules — registry missing commands with no CI signal #39 warns about
• Blocking merge of: PR fix: consolidate _default_db_path to utils.py — closes #40 #71, PR feat: rule-validate + rule-test commands — closes #51 #72 (and any future PR until fixed)