Polish responsive graph viewport

[ktjn]

Summary

• keep automatic graph fitting at a readable 0.8 zoom floor while preserving deliberate overview zoom and pan
• align overflowing dense graphs to a coherent leading subtree instead of an arbitrary centered slice
• refit on meaningful canvas resizes without overriding manual navigation
• compact controls, exports, and the conditional MiniMap so overlays stay clear of nodes
• remove the desktop width cap so the workbench and graph can use ultrawide screens
• add unit and browser coverage for dense modes, resize behavior, overlay clearance, constrained layouts, and ultrawide geometry

Why

Dense Entity and Projection graphs were initially fitted too far out, making labels difficult to read. The default controls and MiniMap also occupied too much of the graph canvas, while the 1920px workbench cap left substantial space unused on large displays.

Impact

Graphs now open at a readable scale and remain pannable when all content cannot fit. Domain and Lineage still center when they fit, dense modes open on a coherent subtree, controls remain compact and unobtrusive, and the playground expands across larger screens.

Validation

• npm test — 370 passed
• npm run check
• npm run build
• npx playwright test --project=chromium — 40 passed
• uv run ruff format .
• uv run ruff check .
• mypy baseline ratchet — passed with 404 current errors and 45 resolved baseline errors
• uv run pytest --tb=short — 1531 passed, 15 skipped
• light/dark screenshots captured for Domain, Entity, Projection, and Lineage, plus constrained and ultrawide Entity views

Documentation review

Doc/spec review passed all four phases: structural validation, reciprocal-link consistency, behavioral coverage, and quality gates.