Bump version to v0.4.0; update README; improve server startup/test robustness and API fixes

[zylzyqzz]

Motivation

• Synchronize package version and public docs with current codebase by bumping to v0.4.0 and updating README.md to reflect implemented features and structure.
• Reduce flaky test failures caused by server startup checks by making model connection and hand-scheduler startup opt-out for test runs.
• Harden and clean up web API request/response handling and chat intent parsing to fix subtle bugs and improve readability.
• Add an audit report documenting current implementation status for maintainers.

Description

• Update package version from 0.1.0 to 0.4.0 in Cargo.toml and Cargo.lock.
• Rewrite README.md to reflect the current project state, CLI, APIs, skills, providers and roadmap aligned with v0.4.0.
• Modify core/api.rs to add environment toggles DIMCLAW_SKIP_MODEL_TEST and DIMCLAW_SKIP_HAND_SCHEDULER on server startup, improve formatting, fix chat intent extraction and session key construction, and tidy various request/response helpers.
• Enhance test harness in tests/support/mod.rs to capture server stdout/stderr to files, set skip env vars when launching test server, increase readiness retry window, and include log tails on startup timeouts; also update src/main.rs CLI about text and defaults to v0.4 strings.
• Add docs/实际开发巡检报告.md as a repository audit/report.

Testing

• Ran cargo test (unit and integration tests) and the test suite completed successfully after the changes.
• Performed a build with cargo build to validate compilation and confirmed the binary launches for the server subcommand under the adjusted test harness.
• Exercised the test server start routine via tests::support::start_server to validate readiness probing and log capture, and related server-start tests passed.

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Codex Task