feat(provider): add OpenCodeProvider for discover command

[TorratDev]

Summary

• Add OpenCodeProvider struct implementing SessionProvider trait to read commands from OpenCode SQLite database
• Add DiscoverProvider enum in discover::mod.rs to select between Claude and OpenCode providers
• Add OPENCODE_DB_PATH constant to hooks::constants.rs

Test plan

• cargo fmt --all && cargo clippy --all-targets && cargo test → 21 passed
• Manual testing: rtk discover --provider opencode -v → 757 Bash commands extracted (on my expirience)

Tests added

• test_opencode_discover_sessions_empty — empty DB returns no sessions
• test_opencode_discover_sessions_with_filter — project filter substring matching
• test_opencode_discover_sessions_since_days — date filter with cutoff
• test_opencode_extract_tool_commands — extract bash tool from OpenCode JSON format
• test_opencode_extract_multiple_tools — multiple tool calls ordered by timestamp
• test_opencode_extract_error_tool — error detection in tool output
• test_opencode_malformed_json_handling — graceful handling of invalid JSON
• test_opencode_empty_directory_handling — NULL/empty directory filtering

I'm not an expert in Rust, so feedback and suggestions are very welcome.

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2 out of 3 committers have signed the CLA.

✅ aeppling
✅ TorratDev
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[pszymkowiak]

[w] wshm · Automated triage by AI

📊 Automated PR Analysis

✨ Type	feature
🟡 Risk	medium

Summary

Adds an OpenCodeProvider that reads session/command history from an OpenCode SQLite database, alongside a DiscoverProvider enum to select between Claude and OpenCode providers in the discover command. Also includes a UTF-8 char boundary helper fix and version bumps to 0.37.2.

Review Checklist

• Tests present
• Breaking change
• Docs updated

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Analyzed automatically by wshm · This is an automated analysis, not a human review.