v0.15.0

Theme: you choose the facts, and the map stops repeating itself.

Added

• --features selects which fact classes the map carries. A budget decides
  how much of the map fits; it could not say what was eligible in the first
  place.
  Twelve named classes (calls, relations, fields, constants,
  decorators, raises, tested, usage, size, private, tests,
  support) can now be dropped whole, with types making thirteen. Gating
  happens at each render site before the budget catalog, so a deselected class
  never enters the adaptive search and cannot be restored by it. The package
  trie, type headers, and public signatures are the map's identity and stay
  unselectable; --features none leaves exactly those. The selection is stamped
  in the footer and recalled like --lang and --budget, and --interactive
  on build/init prices a selection against the full map before writing it.
• --features types. Declared return and parameter types are now a
  selectable fact class, closing a gap between the feature catalog and the
  structure floor: L8 already stripped them, but nothing named them. They cost
  1.0% of this repository's map, 2.8% of a TypeScript corpus and 5.1% of a Java
  one — more than seven of the twelve classes that were already selectable.
• L8, a structure-only floor below the semantic floor. When even L7 cannot fit a
  --budget, Hologram now renders the same facts in project vocabulary alone: return
  and parameter types, decorators and route paths, !throws, ~N/✓/×0 markers,
  {field} lists, and : super / ←impls / sealed: relations all go, leaving the
  source tree, type names, and function names with their parameter names. On this
  repository the floor drops from 714 to 460 tokens. Ranked whole facts still compete
  for slack above it, and the previous "no complete map fits" fallback now runs only
  when L8 overflows too. BudgetStats.skeleton_tokens keeps meaning the L7 semantic
  floor; effective_detail reports L8 or L8-adaptive:n/m.

Changed

• The extension a map repeats is declared once. A title line such as
  # hologram ·.py states the corpus extension, and the file nodes that carry
  it render bare; a leaf that states an extension has exactly the one it
  states. Worth 1.2–1.5% of a real map (57 tokens on a 4,936-token TypeScript
  corpus, 95 on a 6,220-token Java one) and nothing where it would not pay: a
  stem another node already owns (extract/ beside extract.py), a stem still
  holding a dot (shell.component), and corpora too small or too mixed to earn
  the declaration all keep their extensions. Grouped landmarks
  ({ItemId,OrderId}.java(R{value})) keep theirs too, which is what tells a
  reader the bare node above them is a directory.
• The test index states landmarks and support, never call targets. The
  > target +N coverage edge is gone: it spent tokens naming one arbitrary
  target and counting the rest, and what a test file exercises is already
  legible from the case names it carries. ? tests now holds exactly test
  classes, test functions and methods, helper classes, helper functions, and
  declared fixtures.
• Fixtures and shared helper functions are named. A fixture qualifies by
  declaration (@pytest.fixture, @BeforeEach, @Rule, …) because the
  framework injects it by name rather than calling it; a plain function has to
  be used by another test file. Teardown markers earn no name. Both render in
  the existing * group, whose legend clause is now *=helper/fixture.