#7030: feat: add line balancing animation for Double End M12 Cable Assembly

Interactive HTML visualization with: - 3 balancing algorithms (Largest Candidate Time, Ranked Positional Weight, Kilbridge & Wester) - Animated step-by-step station merging - Bar chart with stacked task segments and takt line - Gantt timeline view per station - Efficiency gauge and KPI dashboard - Full process detail table with station assignments - Adjustable station count, algorithm, and animation speed https://claude.ai/code/session_01DNRvjpMpZnjhPPyaynkSTc <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Adds a new self-contained `cable-assembly-line-balancing.html` page implementing an interactive line-balancing visualization for a Double End M12 Cable Assembly. The page includes UI controls for choosing target station count, algorithm, and animation speed; renders a stacked workload bar chart with a bottleneck/takt line, a per-station Gantt timeline, an efficiency gauge, KPI cards, and a detailed process table. Balancing is implemented in-client via three selectable heuristics and animated by generating intermediate “merge” snapshots before updating the final station assignment. <h3>Confidence Score: 3/5</h3> - This PR is reasonably safe to merge, but some algorithm labeling/behavior and snapshot animation failure modes may mislead users. - The change is isolated to a new HTML file and is unlikely to affect the rest of the repo. Main concerns are correctness/expectations: the ‘RPW’ and ‘Kilbridge & Wester’ implementations assume linear precedence and/or don’t match the named method, and `buildSnapshots()` can silently skip merges, causing confusing animations. There are also a few edge-case math guards and minor accessibility gaps. - cable-assembly-line-balancing.html <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) - Context from `dashboard` - AGENTS.md ([source](https://app.greptile.com/review/custom-context?memory=0d0c8278-ef8e-4d6c-ab21-f5527e322f13)) <!-- /greptile_comment -->