test: pin text color, button label placement, star import, and per-path scale cache

[dmccoystephenson]

Summary

Test-only expansion (Stage B of the dev loop). Five characterization tests are added to src/test/python/preponderous/graphik/test_graphik.py for documented behaviors that were not previously pinned. No production code is changed.

• drawText color — glyphs are painted with the requested color: on a black background a red "W" at size 40 produces at least one exactly-red pixel, and every inked pixel is a pure shade of red (no green/blue component from antialiasing against a different hue).
• drawButton label placement — the label sits entirely inside the drawn box, straddles the box midpoint on both axes, and is horizontally centered on it to within 1px (the same tolerance the existing drawText centering test uses, for the same glyph-asymmetry reason).
• drawButton label color — the label is rendered in colorText, not colorBox; a swap of the two arguments (which would make the label invisible against its own box) is caught.
• Star import — from preponderous.graphik import * resolves Graphik through the package's lazy __getattr__ via __all__; a name listed in __all__ that __getattr__ could not serve would make the star import itself raise.
• Scaled-image cache scoping — the (size, surface) pair is kept per filePath, so rescaling one asset leaves another asset's cached scale intact (red at 10→12 does not force blue at 10 to be rescaled).

Each new test was confirmed to fail under a targeted mutation of the behavior it pins (color swapped to white; label anchored at the top-left; colorBox passed to drawText; a single shared cache slot; Graphik dropped from __all__) and to pass on the real code.

Test plan

• python3 -m py_compile src/main/python/preponderous/graphik/graphik.py
• python3 -c "import preponderous.graphik as g; print(g.__version__)" (import smoke test)
• python3 -m pytest -q → 52 passed (47 baseline + 5 new), headless via conftest.py's dummy SDL drivers
• Mutation check: all 5 new tests fail when the pinned behavior is broken, pass when restored
• CI Test workflow green across the 3.9–3.13 matrix

Triage notes

No tracking issue — gap found during triage. The three open issues were all deferred this cycle because each is explicitly maintainer-gated:

• release: version tags are pushed without the 'v' prefix publish.yml requires, so no release has ever been published #34 (release tag prefix) — touches .github/workflows/publish.yml and the release process; the issue body itself defers the choice between the two options to a maintainer.
• ci: test.yml's header comment claims it runs on every push, but pushes outside main are only covered via pull_request #39 (test.yml header comment) — a one-line comment fix, but under .github/workflows/, which is excluded from autonomous change; awaits a maintainer either applying the reword or broadening the trigger.
• packaging: the empty preponderous/__init__.py ships a regular package, which will collide with any future preponderous.* distribution #40 (preponderous/__init__.py namespace package) — the deletion is only safe if sibling Preponderous-Software distributions follow the PEP 420 convention, which cannot be determined from this repository.

A documentation sweep (README, RELEASING.md, pyproject.toml, docstrings) found no drift against the current source, so test expansion was chosen as the work mode.

This PR description was drafted during a Gardener session (https://github.com/Stephenson-Software/gardener).

🤖 Generated with Claude Code

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drafted by Claude on behalf of Daniel Stephenson

[dmccoystephenson]

Self-review rubric (anchored on the green Test workflow, run 35496996740 — 52 passed on each of 3.9/3.10/3.11/3.12/3.13):

• Scope: PASS — one file modified (src/test/python/preponderous/graphik/test_graphik.py, +122 lines), test-only; no production, docs, or version change.
• Tests-new: no signal — no new public method is introduced; the five new tests pin existing documented behavior.
• Tests-fix: no signal — no bug fix in this PR. Substituted check: each new test was mutation-verified (behavior broken → test FAILS; restored → PASS) for the specific regression its comment names.
• Sibling structure: PASS — new tests follow the file's existing patterns (_make_graphik, _rgb, _write_solid_image, _count_image_scales; one _button_label_ink helper added beside the other _-prefixed helpers; comments explain why each pin matters, matching neighbors).
• Sibling renames: no signal — nothing renamed.
• Docs: PASS — README, RELEASING.md, pyproject.toml, and docstrings were swept against the source at triage and found accurate; nothing in this PR changes documented behavior. The one known drift (test.yml header comment) is tracked as ci: test.yml's header comment claims it runs on every push, but pushes outside main are only covered via pull_request #39 and is workflow-gated.
• Issue resolution: no signal — no Closes #N; triage notes in the PR body record why release: version tags are pushed without the 'v' prefix publish.yml requires, so no release has ever been published #34, ci: test.yml's header comment claims it runs on every push, but pushes outside main are only covered via pull_request #39, packaging: the empty preponderous/__init__.py ships a regular package, which will collide with any future preponderous.* distribution #40 were deferred.
• manual validation: PASS — py_compile OK, import smoke OK, python3 -m pytest -q → 52 passed locally; CI matrix green with the executed-test count confirmed in the logs.
• camelCase: no signal — no public method added or renamed.
• Backward-compat: PASS — graphik.py and __init__.py are untouched (git diff --name-only origin/main...HEAD lists only the test file).
• Headless: PASS — the new tests rely on conftest.py's SDL_VIDEODRIVER/SDL_AUDIODRIVER=dummy; they passed on the display-less CI runners.
• Version sync: no signal — no version string changed.
• No new deps: PASS — only pygame, pytest, and stdlib imported.

Observations outside the diff (not blocking): the two exact-color assertions assume a 24/32-bit display surface, which the existing exact-color tests in the file already assume, so no new fragility is introduced. Inline review (code-review skill, medium effort) reported no findings.

This review was drafted during a Gardener session (https://github.com/Stephenson-Software/gardener).

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drafted by Claude on behalf of Daniel Stephenson