fix(fonts): load 4x6 on its pixel grid, from any working directory (#565)

* fix(fonts): load 4x6 on its pixel grid, from any working directory

`extra_small_font` loaded 4x6-font.ttf at 6, off the face's 7px grid.
Under `draw.fontmode = "1"` the mono rasteriser thresholds each glyph at
50% coverage, so every glyph lost its fourth column and deformed:
christmas-countdown rendered "UNTIL" as "VM1JL". The advance is 5px at
both sizes, so snapping to 7 reflows nothing.

- Sizes in DisplayManager._load_fonts go through crisp_size() instead of
  literals. crisp_size / FONT_PIXEL_GRID / FONT_NAME_ALIASES move to
  src/common/font_layout.py; sports_card re-exports them.
- Mirror the fix in VisualTestDisplayManager, the harness's fork of
  _load_fonts. Without it every golden is blessed at the old size.
- Resolve bundled font paths against the install root, not the cwd.
  FontManager._resolve_asset_path now delegates to
  font_layout.resolve_asset_path (kept by name; plugins probe for it).
- The startup banner's middle rung snaps to 7; the 5 rung stays off-grid
  on purpose (the only size that fits a dotted quad on 64px).
- loading.py reads all plugin JSON as UTF-8 (cp1252 on Windows aborted
  check_plugin.py on a 0x9d byte).
- check_plugin.py reports in ASCII and never dies on an unencodable char.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(fonts): resolve relative asset paths from the install root, not the cwd

resolve_asset_path checked os.path.exists(relative_path) unconditionally,
so a relative asset path was still resolved against the process cwd first
-- exactly the dependency this module exists to remove. An unrelated
working directory that happens to contain assets/fonts/4x6-font.ttf (a
stale checkout, a copied assets folder, another project) would shadow the
real bundled font instead of the install root ever being consulted.

Only an absolute path is now returned as-is; a relative path always
resolves against _INSTALL_ROOT first, matching the docstring's stated
contract. FontManager._resolve_asset_path delegates to this function, so
it's covered by the same fix.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

src/font_manager.py

@@ -38,7 +38,7 @@ import time
 from collections import OrderedDict
 from pathlib import Path
 from PIL import ImageFont
-from src.common.font_layout import load_truetype
+from src.common.font_layout import load_truetype, resolve_asset_path
 from typing import Dict, Tuple, Optional, Union, Any, List
 
 logger = logging.getLogger(__name__)
@@ -665,20 +665,14 @@ class FontManager:
     def _resolve_asset_path(relative_path: str) -> str:
         """Resolve a repo-relative asset path independently of the process cwd.
 
-        Prefers the working directory (preserving behavior when the process
-        runs from the install root), then falls back to the install root
-        derived from this module's own location. Without the fallback, any
-        process started outside the install root (e.g. the plugin safety
-        harness on CI) silently loses every font and degrades to PIL's
-        default face.
+        Thin delegate to :func:`src.common.font_layout.resolve_asset_path`,
+        which holds the one definition (``DisplayManager._load_fonts`` needs
+        the same resolution and must not import this class for it). The method
+        stays because plugins probe for it by name to share the core's notion
+        of "install root" -- see the `_resolve_font_path` helpers in the
+        scoreboard plugins.
         """
-        if os.path.exists(relative_path):
-            return relative_path
-        install_root = Path(__file__).resolve().parent.parent
-        candidate = install_root / relative_path
-        if candidate.exists():
-            return str(candidate)
-        return relative_path
+        return resolve_asset_path(relative_path)
 
     def _initialize_fonts(self):
         """Initialize font catalog and validate configuration."""