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>

scripts/check_plugin.py

@@ -35,6 +35,31 @@ sys.path.insert(0, str(PROJECT_ROOT))
 
 os.environ['EMULATOR'] = 'true'
 
+
+def _make_output_encoding_safe() -> None:
+    """Stop an unencodable character from killing the run.
+
+    This script's own report is ASCII, but it echoes text it does not control
+    -- plugin ids, mode names and exception messages -- and a Windows console
+    is cp1252, which cannot encode most of what a plugin might put there. The
+    default 'strict' error handler turns that into a UnicodeEncodeError from
+    inside `print`, so a rendering run that had already succeeded exited
+    non-zero with a traceback instead of printing its results.
+
+    'replace' degrades the offending character to '?' and keeps going; the
+    encoding itself is left alone so output still matches the terminal.
+    """
+    for stream in (sys.stdout, sys.stderr):
+        try:
+            stream.reconfigure(errors='replace')
+        except (AttributeError, ValueError, OSError):
+            # Not a reconfigurable TextIOWrapper (redirected, wrapped by a
+            # test harness). Nothing to do -- this is best-effort hardening.
+            pass
+
+
+_make_output_encoding_safe()
+
 from src.logging_config import get_logger  # noqa: E402
 from src.plugin_system.testing.loading import (  # noqa: E402
     build_full_config, find_plugin_dir, load_harness_spec, load_manifest,
@@ -178,7 +203,7 @@ def print_report(all_results: Dict[str, List[RenderResult]]) -> bool:
                 status = "PASS"
                 detail = ""
                 if r.golden_checked:
-                    detail = " (golden ✓)"
+                    detail = " (golden ok)"
                 if r.update_error is not None:
                     detail += f" (update warn: {r.update_error})"
                 if r.fill_checked and r.fill_ok is None and r.fill_extent:
@@ -196,7 +221,7 @@ def print_report(all_results: Dict[str, List[RenderResult]]) -> bool:
                     status, detail = "FAIL", f" overflow bbox={r.overflow}"
                 elif r.golden_ok is False:
                     status = "FAIL"
-                    detail = f" golden drift: {r.golden_diff_pixels}px (max Δ={r.golden_max_delta})"
+                    detail = f" golden drift: {r.golden_diff_pixels}px (max delta={r.golden_max_delta})"
                 elif r.fill_ok is False:
                     ex, ey = r.fill_extent or (0.0, 0.0)
                     status = "FAIL"