fix(streaming): v8.0.30 audit follow-ups + 8.0.32 bump (closes #498)

[userFRM]

Summary

Closes the seven hygiene gaps identified in the v8.0.30 streaming review (issue #498). One squashable commit; no dispatcher / FFI behavior change for users on the happy path, only on previously-undefined error paths.

• Dispatcher resilience. Drain loop now wraps user-callback invocation in catch_unwind. A panic from user code (Rust closure / PyO3 callable / napi ThreadsafeFunction / C extern "C" fn) no longer kills the dispatcher thread; panics are counted on a new panic_count AtomicU64 (exposed via StreamingDispatcher::panic_count()) and logged at error level. SSOT: every binding inherits this behavior; no per-binding panic handling added.
• FPSS C ABI state machine. TdxFpssHandle gets a permanent state: AtomicU8 field. tdx_fpss_set_callback / _set_inline_callback / _reconnect / _shutdown enforce the documented one-shot registration and terminal-shutdown rules. Post-shutdown ops return -1 with a clear tdx_last_error() string instead of silently re-using a torn-down handle.
• Unified C ABI replacement contract. tdx_unified_set_callback after tdx_unified_stop_streaming is now documented (rustdoc + thetadx.h) as REPLACEMENT, not error. The high-level unified path supports stop+restart as a normal user flow (tdx_unified_reconnect is built on top of it). The contract divergence from FPSS one-shot is intentional and explicit in both header docs.
• ctx lifetime + thread affinity documented in every tdx_*_set_callback / _set_inline_callback declaration in thetadx.h, mirrored in thetadx.hpp doxygen.
• Python dropped_event_count() doc + test corrected to the actual reset-on-reconnect / zero-after-stop semantics. Counter lives on the live dispatcher; reconnect() rebuilds it. Matches the TypeScript binding's contract.
• Dispatcher dropped counter is strictly queue-full. TrySendError::Disconnected (rare; shutdown race) feeds a new disconnected_count so the user-facing drop metric is not inflated by lifecycle noise.
• TypeScript index.d.ts regenerated from the corrected napi-rs rustdoc so the JS-visible doc matches the Rust source.

Version 8.0.30 -> 8.0.31 via scripts/bump_version.py. Changelog mirrored to docs-site/docs/changelog.md.

Closes #498

Test plan

• cargo fmt --all -- --check
• cargo clippy --workspace --all-targets -- -D warnings
• cargo test --workspace
• cargo deny check
• cargo run -p thetadatadx --bin generate_sdk_surfaces --features config-file -- --check
• cargo check --manifest-path tools/mcp/Cargo.toml --locked
• cargo clippy --manifest-path tools/mcp/Cargo.toml --all-targets -- -D warnings
• cargo test --manifest-path tools/mcp/Cargo.toml --no-run
• cargo check --manifest-path tools/server/Cargo.toml --locked
• cargo check --manifest-path sdks/python/Cargo.toml --locked
• cargo check --manifest-path sdks/typescript/Cargo.toml --locked
• python3 scripts/check_version_sync.py
• cmake -S sdks/cpp -B build/cpp && cmake --build build/cpp --target thetadatadx_cpp
• cmake --build build/cpp --target thetadatadx_fpss_smoke
• New unit test dispatcher_survives_panicking_callback in crates/thetadatadx/src/fpss/dispatcher.rs exercises three guaranteed-panic events followed by three successful ones, asserts panic_count == 3 and dropped_count == 0.
• New unit test fpss_state_gate_rejects_after_shutdown in ffi/src/streaming.rs exercises every state-gate transition without needing a live FPSS connection.