Two figures previously shipped with the API reference were not referenced
by any document:
- figures/a2dp.png (under framework/bluetooth/) — A2DP connection state
machine diagram.
- figures/ft_context.svg (under framework/feature/) — Relationship between
the Feature framework interface (ft_value_t / ft_context_ref) and the
frontend runtime (JSValue / JSContext).
Instead of deleting them, both figures are now properly referenced:
- bt_a2dp.md gains a new 'Connection State Machine' section that renders
the A2DP state machine diagram with a description of each state.
- feature_framework_context.md gains a new 'Feature Context and Frontend
Runtime' section that uses ft_context.svg to explain the value/context
mapping between the Feature framework and frontend runtimes.
Chinese and English versions are kept in sync.
Add full English version of API reference docs under docs/en/api/,
covering 69 files across kernel, framework, and network modules.
Additional changes in docs/zh-cn/api/:
- Add bilingual navigation header to all 69 zh-cn API documents,
enabling cross-language switching between Chinese and English versions.
- Fix 16 mis-placed function descriptions in telephony/telephony_call.md
where multiple APIs incorrectly shared the same description
(re-derived from the tapi_call.h header @brief comments).
- Fix 2 untranslated English residues in network/wapi.md.
zhangxiaowei16