server + ui: ping silent SSE streams every 1s and kick only after 3s so slow prefill never drops healthy connections (#25241) server + ui: ping silent SSE streams every 1s and kick only after 3s so slow prefill never drops healthy connections server + ui: sse_ping_interval becomes a per-request body field Address review from ngxson: the global default returns to 30 so API clients see no behavior change, and the WebUI sends sse_ping_interval: 1 in the request body since it owns the 3s visibility-kick contract and declares the cadence it needs. Positive values keep the existing > 0 gate, -1 keeps its disabled semantics.

server: move sse_ping_interval into the request schema Address review from ngxson: the field is now a typed field_num with hard limits (-1, INT32_MAX) bound to task_params, seeded from the CLI default alongside the other inherited parameters. The raw json_value read and its redundant comment are gone, and schema evaluation brings type and range validation for free. macOS/iOS: macOS Apple Silicon (arm64) macOS Apple Silicon (arm64, KleidiAI enabled) DISABLED macOS Intel (x64) iOS XCFramework Linux: Ubuntu x64 (CPU) Ubuntu arm64 (CPU) Ubuntu s390x (CPU) Ubuntu x64…