feat: Add French G2P support

FR_PHONES.md

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+# Misaki French Phonemes
+
+**Author**: Patrice
+**License**: Apache 2.0
+
+This document describes the phoneme inventory used by the Misaki French G2P module.
+
+## Overview
+
+French uses approximately **37 phonemes** including:
+- 12 oral vowels
+- 4 nasal vowels
+- 3 semi-vowels (glides)
+- 18 consonants
+
+Unlike English, **French has no lexical stress** - stress is predictable (final syllable of a phrase). Therefore, stress marks (`ˈ`, `ˌ`) are not used.
+
+## Phoneme Inventory
+
+### Oral Vowels (12)
+
+| IPA | Example | French Word | Notes |
+|-----|---------|-------------|-------|
+| i | /i/ | s**i**, l**i**t | close front unrounded |
+| e | /e/ | ét**é**, n**e**z | close-mid front unrounded |
+| ɛ | /ɛ/ | f**ai**t, p**è**re | open-mid front unrounded |
+| a | /a/ | p**a**tte, l**à** | open front unrounded |
+| ɑ | /ɑ/ | p**â**te | open back unrounded (rare) |
+| ɔ | /ɔ/ | s**o**l, m**o**rt | open-mid back rounded |
+| o | /o/ | s**o**t, **eau** | close-mid back rounded |
+| u | /u/ | s**ou**s, g**oû**t | close back rounded |
+| y | /y/ | s**u**, r**ue** | close front rounded |
+| ø | /ø/ | f**eu**, d**eux** | close-mid front rounded |
+| œ | /œ/ | s**eu**l, p**eu**r | open-mid front rounded |
+| ə | /ə/ | l**e**, pr**e**mier | schwa (mid central) |
+
+### Nasal Vowels (4)
+
+| IPA | Example | French Word | Notes |
+|-----|---------|-------------|-------|
+| ɑ̃ | /ɑ̃/ | **an**, t**em**ps, v**en**t | open back nasal |
+| ɛ̃ | /ɛ̃/ | v**in**, p**ain**, s**ein** | open-mid front nasal |
+| ɔ̃ | /ɔ̃/ | b**on**, p**on**t | open-mid back nasal |
+| œ̃ | /œ̃/ | br**un**, parf**um** | open-mid front rounded nasal |
+
+> **Note**: In modern Parisian French, /œ̃/ is merging with /ɛ̃/. Many speakers pronounce "brun" as /bʁɛ̃/.
+
+### Semi-Vowels / Glides (3)
+
+| IPA | Example | French Word | Notes |
+|-----|---------|-------------|-------|
+| j | /j/ | **y**eux, f**i**lle | palatal approximant |
+| w | /w/ | **ou**i, l**oi** | labio-velar approximant |
+| ɥ | /ɥ/ | l**u**i, n**u**it | labio-palatal approximant |
+
+### Consonants (18)
+
+| IPA | Example | French Word | Notes |
+|-----|---------|-------------|-------|
+| p | /p/ | **p**as | voiceless bilabial plosive |
+| b | /b/ | **b**as | voiced bilabial plosive |
+| t | /t/ | **t**a | voiceless dental plosive |
+| d | /d/ | **d**a | voiced dental plosive |
+| k | /k/ | **c**as | voiceless velar plosive |
+| ɡ | /ɡ/ | **g**are | voiced velar plosive |
+| f | /f/ | **f**a | voiceless labiodental fricative |
+| v | /v/ | **v**a | voiced labiodental fricative |
+| s | /s/ | **s**a | voiceless alveolar fricative |
+| z | /z/ | **z**oo | voiced alveolar fricative |
+| ʃ | /ʃ/ | **ch**at | voiceless postalveolar fricative |
+| ʒ | /ʒ/ | **j**our | voiced postalveolar fricative |
+| m | /m/ | **m**a | bilabial nasal |
+| n | /n/ | **n**a | alveolar nasal |
+| ɲ | /ɲ/ | a**gn**eau | palatal nasal |
+| ŋ | /ŋ/ | par**k**i**ng** | velar nasal (loanwords) |
+| l | /l/ | **l**a | alveolar lateral |
+| ʁ | /ʁ/ | **r**a | uvular fricative |
+
+## Phoneme Mappings from espeak-ng
+
+The module maps espeak-ng output to standardized IPA:
+
+```python
+E2K = {
+    'ʀ': 'ʁ',  # Trill to fricative
+    'r': 'ʁ',  # Alveolar to uvular
+    'g': 'ɡ',  # ASCII to IPA g
+}
+```
+
+## Comparison with English
+
+| Feature | English | French |
+|---------|---------|--------|
+| Lexical stress | Yes (ˈ, ˌ) | No |
+| Nasal vowels | No | Yes (4) |
+| Front rounded vowels | No | Yes (y, ø, œ) |
+| R sound | ɹ (alveolar) | ʁ (uvular) |
+| Vowel length | Contrastive | Not contrastive |
+| Diphthongs | Many | Few (oj, ɛj, etc.) |
+
+## Common Pronunciation Patterns
+
+### The "-ait/-ais" endings (imparfait)
+
+These should be pronounced /ɛ/ (like "è"):
+
+- était → /etɛ/
+- faisait → /fəzɛ/
+- savait → /savɛ/
+- allait → /alɛ/
+
+### The "-ain/-ein" endings (nasal)
+
+These should be pronounced /ɛ̃/:
+
+- main → /mɛ̃/
+- plein → /plɛ̃/
+- pain → /pɛ̃/
+
+### Silent letters
+
+French has many silent final consonants:
+
+- fait → /fɛ/ (t silent)
+- temps → /tɑ̃/ (ps silent)
+- les → /le/ (s silent, unless liaison)
+
+### Liaisons
+
+Liaisons occur when a normally silent consonant is pronounced before a vowel:
+
+- les amis → /le.z‿ami/
+- un homme → /œ̃.n‿ɔm/
+
+## References
+
+- [French phonology - Wikipedia](https://en.wikipedia.org/wiki/French_phonology)
+- [Help:IPA/French - Wikipedia](https://en.wikipedia.org/wiki/Help:IPA/French)
+- [Appendix:French pronunciation - Wiktionary](https://en.wiktionary.org/wiki/Appendix:French_pronunciation)