ss v0.8.4

Added

• Added explicit optional member access with ?. for records and objects,
  including chained access and fallback values with ??.
• Added Markdown ==highlight== syntax and fenced-code line highlights such
  as {2-3,5}, with configurable highlight colors in PDF and HTML output.
• Added Markdown table column widths with {100pt}, {1fr}, and {auto}
  annotations.
• Added typed semantic roles and heading levels for slide objects, including
  custom object classes and HTML output.
• Added alignment snapping with visual guides in the VS Code WYSIWYG editor.

Changed

• Unified function evaluation across direct calls, function values, callbacks,
  and statement and expression positions. Void is restricted to function
  results; its calls execute as statements, and Void functions use bare
  return without an expression.
• Made constraint registration explicit through constrain! and
  constrain_on!. Returning a Constraints value or using it as a statement
  no longer registers it. ~ statements continue to register constraints in
  the current page context.
• Changed page_anchor to require both a page and an anchor name, such as
  page_anchor(pagectx(), "left"). Constraint registration checks that page
  anchors refer to the page receiving the constraints.
• Separated object creation from page placement. Unplaced objects and groups
  are valid values and are excluded from document object queries; placement
  includes only explicitly grouped descendants and rejects repeated placement.
  page_of now returns Page?, and framed components return groups containing
  their content and decoration.
• Restricted stored properties to types without functions or unconstrained
  Any, including fields nested in records and optional values. Local records
  can still contain functions, and display callbacks are registered with
  set_repr.
• Enforced read-only display evaluation: display callbacks cannot modify
  properties, create objects or pages, register displays, or read external
  files, including through helpers and callbacks.
• Made continuous page display the only WYSIWYG editor mode, with sidebar
  selection scrolling to the selected page. Removed the single-page mode
  selector and per-page presentation buttons, and required five CSS pixels
  of pointer movement before starting an object drag.
• Separated layout results from evaluated document state, keeping solved
  geometry out of source objects. Made analysis, evaluation, page preparation,
  layout solving, rendering, preview reuse, and cache ownership explicit across
  the CLI and editor pipelines.
• Managed the bundled MD4C fork with Git subtree and retained its upstream
  regression suites (#19). Contributed by @abap34.

Fixed

• Corrected type checking for required record fields, function parameter
  variance, callbacks, optional members, property access, and selections.
  Complete property paths now reject duplicate and overlapping definitions
  while preserving independently defined sibling fields.
• Unified lexical name resolution across static analysis, evaluation, hover,
  and definition, including local shadowing, qualified calls, lambda
  parameters, and incomplete import aliases.
• Corrected static fact joins across return paths and selection operations so
  unknown or conflicting results do not recover unjustified literal values,
  object classes, or property identities.
• Corrected static recursion detection for cross-module lambdas, captured
  records, optional function values, and display functions, preserving the
  defining module and captured environment through higher-order calls.
• Corrected dependency analysis for captured environments, function values,
  omitted arguments, object aliases, nested anchors, and display functions.
  Dependency scheduling preserves authored composition order and reports the
  resources involved in actual cycles.
• Shared semantic analysis across bounded LSP queries, preserved diagnostics
  for independent documents and failed imports, and rescheduled canceled
  rebuilds. Excluded strings and comments from semantic queries, ended folding
  ranges on closing lines, and improved completion and recovery without
  cascading diagnostics from failed bindings.
• Preserved direct and nested object references and explicitly absent optional
  properties in dump. Kept empty editor snapshots and layout reports
  consistent with the populated JSON response structure.
• Corrected Markdown block spacing, split-group sizing after width allocation,
  and theme colors for Markdown code blocks.
• Corrected ownership and allocation-failure handling in analysis and document
  state, and bounded evaluator call frames, recursion, and execution resources.