feat: complete release readiness work

- consolidate API ownership and remove dead vendor code

- add Stripe billing, learning paths, and public CV hardening

- add migration, recovery, security, audit, and browser gates

JobTrackerApi/Services/JobCvMatchService.cs

@@ -148,7 +148,7 @@ namespace JobTrackerApi.Services
             var frequencies = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
             foreach (var token in Tokenize(jobText))
             {
-                if (token.Length < 3 || StopWords.Contains(token) || IsNumeric(token)) continue;
+                if (token.Length is < 3 or > 64 || StopWords.Contains(token) || IsNumeric(token)) continue;
                 frequencies[token] = frequencies.TryGetValue(token, out var c) ? c + 1 : 1;
             }