fix(tokenizer): bound retry ladder and cache, fix name-match edge cases

- Cap only blind shrinking-window retries (not backend-guided shrinks); a line that exhausts the cap escalates to one parseText fallback instead of dropping to raw text
- Bound the cross-line termsFind cache by retained dictionary-entry weight, not just key count, and re-check it when a lookup resolves
- Keep halfwidth katakana character names in the greedy pre-pass, and let a generic word beat a name it fully contains
- Share one Han code-point table between the character dictionary and the scanner's name pre-pass; narrow the mob-disambiguator filter to the split letters, not every one-character term
- Release the subtitle prefetch pause on a new onProcessingSettled signal instead of the tokenized emit, so duplicate/suppressed/failed lines no longer pause prefetch indefinitely
- Split the Yomitan scan runtime's injected helper script into its own file

src/core/services/tokenizer/yomitan-parser-runtime.ts

@@ -1042,6 +1042,19 @@ export async function requestYomitanScanTokens(
       await ensureYomitanScanNameCandidates(parserWindow, nameCandidates, logger);
       rawResult = await parserWindow.webContents.executeJavaScript(callScript, true);
     }
+    // The scanner reports a line where a position ran out of shrinking-window
+    // retries: it stopped short of windows an uncapped ladder would have tried,
+    // so a real term may be sitting in an unparsed run. One parseText for the
+    // line is the bounded way to get the exhaustive answer back (this is the
+    // parse the scanner replaced, and it only runs for these rare lines).
+    if (isObject(rawResult) && rawResult.retryBudgetExhausted === true) {
+      logger.info?.('Yomitan scanner exhausted its retry budget; parsing the line as a fallback.');
+      const fallbackTokens = await requestYomitanParseFallbackTokens(text, deps, logger);
+      if (fallbackTokens) {
+        return fallbackTokens;
+      }
+      rawResult = rawResult.tokens;
+    }
     if (isScanTokenArray(rawResult)) {
       // Filler-only results carry no dictionary match; keep the historical
       // contract of returning null so callers fall back to raw text.