Replace grammar-ending permutations with shared matcher; preserve word a

- Extract `grammar-ending.ts` with `isStandaloneGrammarEndingText` / `isSubtitleGrammarEndingText` pattern matchers
- Replace `STANDALONE_GRAMMAR_ENDINGS` set in parser-selection-stage with shared matcher
- Replace generated phrase sets in subtitle-annotation-filter with shared matcher
- Remove stale duplicate subtitle-exclusion constants and helpers from annotation-stage
- Manual clipboard card updates now write only to the sentence audio field, leaving word/expression audio untouched

changes/321-grammar-ending-pattern-filter.md

@@ -0,0 +1,5 @@
+type: fixed
+area: tokenizer
+
+- Tokenizer: Replaced hard-coded standalone grammar-ending permutations with shared pattern matching for polite copula, negative copula, and explanatory subtitle endings.
+- Tokenizer: Kept grammar annotation exclusion logic in the shared subtitle filter and removed stale duplicate exclusion helpers from the annotation stage.

changes/322-preserve-word-audio-manual-update.md

@@ -0,0 +1,4 @@
+type: fixed
+area: anki
+
+- Anki: Manual clipboard subtitle updates now preserve existing word audio while replacing sentence audio and animated-image media.