feat: add intended language selector with context inference to Fixes UI and bump to v1.0.8

• Infer intended language from preceding words to prevent false detection on typos (e.g. 'Whole sandwitch' -> 'Whole sandwich')
• Add interactive Intended Language dropdown in Fixes tab with live re-checking
• Add l10n translations for all 10 supported UI languages
• Add unit tests for context inference, language options, and alignments
• Bump extension version to 1.0.8 across manifests and documentation