Extend the Diagram Doctor beyond flowcharts to stateDiagram / stateDiagram-v2.
- New parseStateDiagram: states → nodes, transitions → edges in source order
(including `[*]` pseudo-transitions, so linkStyle indices stay aligned);
`[*]` itself is never a node. Composite states map to groups, notes are
skipped. A parseDiagram() dispatcher feeds analyze/transforms.
- Fixes are tailored per kind (verified empirically against Mermaid 11):
* ELK is flowchart-only (state diagrams reject `layout: elk`), so it's not
offered and the no-ELK score penalty is skipped for state diagrams.
* Spacing uses the `state` config key; direction is set via a `direction`
statement rather than the header.
* State diagrams can't style individual transitions — a `linkStyle` line
renders as a stray node — so the dim-hubs fix and focus mode fade the
busy *states* (e.g. CANCELLED) via classDef/class instead of dimming edges.
Flowcharts keep edge dimming via linkStyle.
- Panel notice now covers flowcharts & state diagrams.
Verified in-browser: state-diagram dim/focus render with zero junk nodes;
flowchart ELK + linkStyle dimming still intact.
Add an Optimize side panel that analyses the active flowchart and applies
one-click, reversible source rewrites to make dense graphs readable.
- optimize.ts: pure, label-aware flowchart parser + metrics, a 0-100
readability score, and transforms — ELK layered layout, node/rank
spacing + curved edges, de-emphasising cross-cutting hub edges
(event bus / audit / cost-style fan-ins), duplicate-edge removal,
direction toggle, and a non-destructive focus variant.
- mermaid.ts: register @mermaid-js/layout-elk so `layout: elk` renders.
- OptimizePanel.svelte + Toolbar toggle; panels are mutually exclusive.
- Preview: render the focus variant when a node is spotlighted, with a
clear-focus pill.
- store/Editor: applySource() bumps a revision so programmatic rewrites
re-sync CodeMirror and stay undoable with the editor's history.
