- Made resolveShapeForText choose silver16-bw for CJK-heavy auto transcripts while preserving explicit variants and unsafe glyph protection.
- Added silver16-bw to the snapcompact shape settings submenu and renamed unsupported-glyph warnings.
- Covered auto shape selection, explicit variant precedence, unsafe glyph scans, and settings option parity.
Fixes#4486
The auto-snapcompact non-ASCII fallback test seeded a single CJK turn with a
245k-token usage. claude-sonnet-4-5's 200k context window made that an input
overflow, so the recovery path dropped the assistant turn and left nothing to
summarize; the default 20k keep-recent window also kept both tiny messages.
Either way prepareCompaction returned undefined, the renderability preflight
never ran, and the strategy stayed "snapcompact" instead of downgrading to
context-full.
Derive the synthetic prompt size from the active model's context window (above
the auto-compaction threshold, below the window) and force keepRecentTokens=1
so the CJK history is always summarized and scanned, regardless of model
metadata.
Auto-compaction now falls back to context-full on any snapcompact preflight or post-render rejection (non-ASCII, kept history too large, projection overflow), matching the text-only-model handling. Manual /compact snapcompact keeps its local-only failure contract per #3599.
Fixes#3659
roboomp