fix(cli): surface contract read failures in gitt issues list

[carlos4s]

Summary

gitt issues list used to treat contract-read failures as an empty issue list. When the RPC/contract read failed, the helper returned [], so the command emitted success: true, issue_count: 0, and exited 0.

This PR makes contract-read failures explicit:

• gitt issues list --json now emits success: false with error.type == "read_failed" and exits 1.
• Human mode now prints the read error and exits 1.
• A reachable contract with zero issues still returns success: true, issue_count: 0, issues: [], and exits 0.
• Missing substrateinterface now returns error.type == "missing_dependency" and keeps the Install with: uv sync hint.

The fix also lets deeper contract-info / packed-storage read failures propagate instead of being silently converted to [] / None.

fetch_issue_from_contract, used by gitt issues submissions --id ..., now also surfaces contract-read failures instead of turning them into the misleading Issue ID <N> not found on-chain. message.

Related Issues

Closes #1357

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other

Before / After

JSON mode before

$ uv run gitt issues list --rpc-url ws://127.0.0.1:1 --contract 5GrwvaEF5zXb26Fz9rcQpDWS2Tw7Rn3myGUFcLDN7Jxxpx12 --json
Network: custom • Contract: 5GrwvaEF5zXb...xxpx12
Error reading from contract: [Errno 111] Connection refused
{
  "success": true,
  "issue_count": 0,
  "issues": []
}
$ echo $?
0

JSON mode after

$ uv run gitt issues list --rpc-url ws://127.0.0.1:1 --contract 5GrwvaEF5zXb26Fz9rcQpDWS2Tw7Rn3myGUFcLDN7Jxxpx12 --json
Network: custom • Contract: 5GrwvaEF5zXb...xxpx12
{"success": false, "error": {"type": "read_failed", "message": "Error reading from contract: [Errno 111] Connection refused"}}
$ echo $?
1

Human mode after

$ uv run gitt issues list --rpc-url ws://127.0.0.1:1 --contract 5GrwvaEF5zXb26Fz9rcQpDWS2Tw7Rn3myGUFcLDN7Jxxpx12
Network: custom • Contract: 5GrwvaEF5zXb...xxpx12

✗ Error reading from contract: [Errno 111] Connection refused

$ echo $?
1

Testing

Added regression tests for:

• JSON contract-read failure returns success: false and exits non-zero.
• Human contract-read failure exits non-zero and does not print No issues found.
• Empty reachable contract still succeeds with issue_count: 0.
• Deeper storage-read failure propagates as read_failed.
• Missing dependency keeps the uv sync install hint.
• gitt issues submissions --json surfaces contract-read failure as success: false instead of issue not found.

Commands run:

uv run pytest tests/cli/test_issues_list_json.py -q
uv run pytest tests/cli/test_issues_list_json.py tests/cli/test_issue_submission.py -q
uv run pytest tests/ -q
uv run ruff check gittensor/ tests/
uv run ruff format --check gittensor/ tests/
uv run pyright gittensor/cli/issue_commands/helpers.py gittensor/cli/issue_commands/view.py tests/cli/test_issues_list_json.py
uv run pre-commit run --hook-stage pre-push --files <changed files>

Checklist

• Code follows project style guidelines
• Self-review completed
• Tests added/updated