fix(ir): validate identities and literals with distinct boolean types

[LunaStev]

Malformed modules can currently pass verification with duplicate IDs, inconsistent type metadata, or constants outside their declared type. AST lowering also accepts duplicate function/parameter names, silently wraps oversized integer literals, and discards expressions returned from void functions. This change rejects those inputs and separates boolean values from one-bit integers.

IR behavior

• Give booleans their own Type::Bool / bool representation. Type::I1 is a signed one-bit integer (-1 or 0), and Type::U1 is an unsigned one-bit integer (0 or 1). Ordinary integer literals with value 1 remain supported in their respective ranges.
• Return bool from comparisons and use it in checked-arithmetic result tuples. Branch, select, and trap conditions require bool; integers are not implicitly converted.
• Reject duplicate block/value IDs and duplicate, missing, contradictory, or orphan value-type entries. Validate derived instruction result types against the metadata table.
• Validate constant categories and signed/unsigned ranges, including global initializers. Global alignment must be an explicit nonzero power of two; alignment 0 is not an automatic-layout marker in completed IR.
• Share literal range validation between function expressions and constant initializers. Invalid typed literals are diagnosed before wrapping can change their value. Existing arithmetic evaluation in required constant initializers is preserved.
• Keep function and global variable namespaces separate, as agreed in the design discussion: a function and global with the same name are valid, while duplicates within either namespace are rejected by lowering and direct module verification.
• Reject duplicate parameter names before lowering bodies, and reject value-bearing returns from void functions.

Compatibility: callers previously using Type::I1 for booleans must migrate to Type::Bool. Printed boolean types change from i1 to bool; the frontend JSON Bool representation is unchanged.

Repository changes

Refresh README with accurate capability descriptions, standalone assembly/IR examples, contributor links, and sponsorship information. Remove the three tracked docs/ files and ignore /docs/ as requested; local documentation remains on disk and the new local design notes are not included in this PR.

IR changes and the README/document-tracking changes are separate signed-off commits.

Validation

Executed locally on Linux with Rust/Cargo 1.96.0:

• cargo test --workspace --locked --offline: 56 passed.
• cargo test --workspace --all-features --locked --offline: 70 passed.
• cargo test -p ir --all-features --release --locked --offline: 35 passed.
• Strict workspace Clippy with all targets, in both default and all-features configurations.
• cargo fmt --all -- --check, warning-free workspace rustdoc, and git diff --check.
• Standalone CLI smoke checks with socket support enabled and disabled.
• README assembly, JSON lowering, and raw-byte object examples executed with the existing debug binary; JSON syntax and local README links checked.

New identity regressions failed against the original verifier before the fix. Regression coverage includes separate namespaces, bool/i1/u1 distinctions, scalar constant boundaries, explicit global alignment, malformed metadata, parameter bindings, void returns, and retaining runtime 1 + 2 as constants plus an add instruction in O0 IR.

SSA dominance/phi validation, complete instruction type verification, pointer safety, target ABI layout, and the broader arithmetic/optimization contracts remain separate work. This PR does not claim complete UB-free execution or a finished O0 pipeline.

Fixes #46
Fixes #47
Fixes #48
Fixes #49
Fixes #140
Fixes #141
Fixes #144