Runtime autonomy release-candidate branch

[ProfRandom92]

Summary

This draft PR isolates the runtime-autonomy release-candidate work on top of fusion/ctxt-runtime-only.

It adds deterministic runtime-contract coverage and release-readiness hardening without enabling provider calls, network behavior, external agent execution, production MCP support, or crates.io publishing.

Changes

• Align DSL validation to the local-fixture-v1 subset.
• Add deterministic validation matrix documentation.
• Add encode JSON shape smoke coverage.
• Add clean trace heuristic smoke coverage.
• Clean up release-readiness blockers:
  • clippy warning
  • Cargo package metadata
  • package exclusions for local-only artifacts
  • README MCP wording
• Align RELEASE_NOTES_v0.1.0.md with the current local runtime scope.

Boundaries

• No crates.io publish.
• No production MCP support claim.
• No full MCP compliance claim.
• No provider gateway.
• No network runtime.
• No external agent execution.
• No proposal/review auto-apply.

Local validation

Local validation passed:

• cargo fmt --check
• cargo check
• cargo test
• cargo clippy -- -D warnings
• cargo package --list --allow-dirty
• cargo test --release

Observed local timing:

• cargo test --release: 36.15s
• cargo clippy -- -D warnings: 2.73s

Review intent

Draft/experiment PR for visibility and review only.
Do not merge into main directly.

[gemini-code-assist]

Code Review

This pull request refines the local-first runtime contract of the ctxt CLI. It updates the DSL validator to reject legacy executable blocks (such as tools and tasks) while adding support for local-only syntax, updates documentation with a deterministic validation matrix, and introduces several smoke tests. The review feedback highlights two valuable improvement opportunities in src/runtime.rs: using strip_prefix instead of trim_start_matches to avoid repeatedly stripping prefixes, and optimizing the legacy block check to prevent unnecessary string allocations by performing case-insensitive checks in-place.

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[gemini-code-assist]

Using trim_start_matches with a string literal prefix like "use:" can be error-prone and misleading, as it repeatedly strips the prefix if it appears multiple times (e.g., "use:use:abc" becomes "abc").

To ensure the prefix is stripped exactly once and in a more idiomatic Rust fashion, use strip_prefix combined with map_or.

Suggested change

	fn valid_use_directive(line: &str) -> bool {
	let name = line.trim_start_matches("use:");
	valid_identifier_body(name)
	}
	fn valid_use_directive(line: &str) -> bool {
	line.strip_prefix("use:")
	.map_or(false, valid_identifier_body)
	}

[gemini-code-assist]

Calling to_ascii_lowercase() on every line during DSL validation allocates a new String each time, which introduces unnecessary memory overhead.

We can perform case-insensitive prefix checks without any allocations by using line.get(..prefix.len()) and eq_ignore_ascii_case.

fn looks_like_block_legacy_semantic(line: &str) -> bool {
    let starts_with_ignore_case = |prefix: &str| {
        line.get(..prefix.len())
            .map_or(false, |sub| sub.eq_ignore_ascii_case(prefix))
    };
    starts_with_ignore_case("oauth")
        || starts_with_ignore_case("provider")
        || starts_with_ignore_case("shell ")
        || starts_with_ignore_case("exec ")
        || starts_with_ignore_case("run ")
        || starts_with_ignore_case("http://")
        || starts_with_ignore_case("https://")
        || starts_with_ignore_case("resource://")
}