Add conditional styling for vertex and edge types

[jkemmererupgrade]

Description

Adds an optional conditional style per vertex and edge type. When a rendered entity's attribute satisfies a condition, an alternate style is layered on top of the base style — useful for flagging states (e.g. a Person node with known_bad = true) without defining a separate type.

• One condition per type. The conditional pane in each style dialog reuses the base style controls and overrides only the fields you change; type-level fields (display name/description) stay in the base pane.
• Condition = attribute + operator + value. Operators: =, !=, >, <, >=, <=, and matches — a *-wildcard text pattern (e.g. Jo*), where every other character is matched literally so regex metacharacters carry no special meaning. The text operators (=, !=, matches) have a case-sensitivity toggle, case-sensitive by default (conditions saved before the flag existed keep the original case-sensitive behavior). Comparison is otherwise type-aware and evaluated in JavaScript at render time: numeric when both sides are numbers, chronological when both parse as dates (handles ISO and non-ISO formats like M/D/YYYY), lexicographic otherwise. Matching is surfaced to Cytoscape via a conditionMet flag rather than Cytoscape's value-selector operators, which compare lexicographically / via parseFloat and mishandle dates.
• Precedence. Selection, focus dimming, and hidden states always take visual priority over a conditional style (Cytoscape's order-based cascade).
• Import / export / reset. Conditional styles ride the existing shared-file-envelope format and the styling storage, so they are saved, imported, and reset with no file-format version bump. In the selective import modal, a type that carries a condition shows a separate, independently selectable "conditional" tile right after its base tile (Base → When-met previews + the condition), so you can import a base style with or without its condition.

Reintegrated onto the current styling architecture after the node/edge styling sidebar was combined (#1914) and the styles cascade collapsed to a single user layer (#1981).

Validation

• pnpm checks passes with no errors; pnpm test passes (2385 tests); pnpm coverage clears all thresholds without changing them.
• A full headless-Cytoscape pipeline test drives condition evaluation + selector generation + the applied stylesheet and asserts only the matching entity receives the conditional color — covering numeric, ISO date, non-ISO (M/D/YYYY) date, boolean, and wildcard (matches) conditions.
• Manually validated in a locally built Docker image against a live graph: styling only matching entities, correct non-ISO date comparison, wildcard matching, dialogs, and the selective import tiles.

Related Issues

Related to #1785 (property-based node styling). This is a partial step: it covers the single-condition case — differentiating entities that meet one condition (e.g. known_bad = true, or risk_score > 90 → red) — which handles the fraud use case the issue leads with. It does not yet cover the issue's other examples: mapping one property to several distinct icons (e.g. gender → distinct icons) or mapping a numeric property to a color gradient. Those would be follow-on work.

Check List

• I confirm that my contribution is made under the terms of the Apache 2.0 license.
• I have verified pnpm checks passes with no errors.
• I have verified pnpm test passes with no failures.
• I have covered new added functionality with unit tests if necessary.
• I have updated documentation if necessary.

🤖 Generated with Claude Code

[jkemmererupgrade]

Hey @kmcginnes, Thank you for merging the node-styling! I refactored the simple conditional styling PR I had to use the latest and put it up as a direct PR and closed mine. Style import and Export as you have it works and brings along the conditional styling as well.

[jkemmererupgrade]

Applying conditional styling to a node:

[jkemmererupgrade]

Updated to include the conditional styling as tiles in the import panel, fixed conflicts.