strop v0.28.0

Picker visual polish (0050) and the multibuffer's missing paint.

Added — picker rows rebuilt per kind (0050)

• Symbols: fixed-width quiet kind chips (all names share one left
  edge across fn/field/variant), container in the secondary role,
  location right-aligned. Four quiet kind families (callables/types/
  data/modules); chips are passive type info, never bright buttons.
• Files: basename first and bright, the parent path secondary at the
  right edge, middle-elided without dropping the disambiguator; query
  matches emphasize in whichever field they hit.
• Grep: two-line hits — filename + directory, then a code window
  built around the REAL rg submatch (never the first 80 chars of the
  line), with the match amber/bold. Line numbers in the secondary role.
• Selection is one band: the whole allocated row — marker, fields,
  blanks — carries the selection background; query evidence survives on
  top of it.
• Honest counts and states: filtered lists show visible / total;
  an empty filter explains itself (No symbols match “zzz” + the way
  out); errors stay actionable.
• Responsive layout: the decision list takes ~60% (65% for grep) of
  the card; narrow terminals stack a short preview below instead of two
  slivers; the scrollbar column is reserved before text budgets and
  never overwrites evidence. Preview headers identify file:line first.

Added — multibuffer paint (0049 §6 remainder)

• Syntax highlighting in excerpts: body rows project the source
  document's own analysis spans into the view — never a synthetic
  combined parse.
• Query hits paint in excerpt bodies (amber/bold), sourced from the
  picker's real submatch geometry; LSP/symbol navigation payloads never
  fabricate a one-byte match.
• Focused card: the caret's card brightens its border and path.
• ]f / [f walk file cards (next/previous), recorded in the
  jumplist.

The picker renderer split into render/picker/{mod,rows,preview}.rs by
responsibility (0050 §9).