Summary

This changes Deno.serve so automatic response compression is off by default.

• flips the runtime default for automatic_compression to false
• keeps explicit automaticCompression: true as the opt-in path
• updates DENO_SERVE_AUTOMATIC_COMPRESSION docs so 1/true enable compression by default
• updates the Deno.serve type docs to show automaticCompression defaults to false
• adjusts serve tests so compression behavior coverage opts in explicitly, and adds/updates coverage for default-off and env-var behavior

Validation

• ./tools/format.js cli/args/flags.rs ext/http/lib.rs tests/unit/serve_test.ts cli/tsc/dts/lib.deno.ns.d.ts
• cargo test -p deno_http compression_tests
• cargo test unit::serve_test -- httpServerAutomaticCompression --nocapture