Always-annotate types in option/result/empty list literals

[colinrozzi]

Summary

Make the value literal format truly lossless for chain replay.

The format added in #13 had a hidden lossiness: two Value instances with different stored type info could produce identical Display output. For example:

• Value::Result { ok_type: String, err_type: String, value: Ok(Tuple([])) } displays as ok<string>(())
• Value::Result { ok_type: Tuple([]), err_type: String, value: Ok(Tuple([])) } also displays as ok<string>(())

Different stored types → different CGRF bytes → different chain hashes → replay diverges.

Fix

Always annotate the type info that can't be inferred from the value:

Before	After
none	none<list<u8>>
some(42u32)	some<u32>(42u32)
ok(42u32)	ok<u32, string>(42u32)
err("bad")	err<u32, string>("bad")
[]	[]<u8>

Non-empty lists still infer elem_type from the first item.

Verification

• All 24 packr-abi tests pass, including new test_cgrf_round_trip that asserts byte-identical CGRF after Display → parse → encode for the cases that previously diverged.
• cargo clippy -p packr-abi -- -D warnings clean.
• End-to-end: a recorded theater chain now replays with full hash verification (Replay complete: 4/4 events verified via streaming).

🤖 Generated with Claude Code