Proposal: lightweight, review-first code navigation without turning Orca into a full IDE

[ridsync]

Orca's core value is managing agent-driven work and reviewing the resulting code changes. I do not think Orca needs to become another VS Code or Cursor.

However, developers still rely on familiar editor workflows when reviewing code or making small fixes:

1. Consistent syntax highlighting across files and diff views
2. Symbol context for files, functions, and classes, with navigation to definitions and references
3. Structural folding for functions, classes, and other scopes

Since Orca already uses Monaco, I propose extending the existing editor and review surfaces instead of embedding another editor.

Proposed capabilities

1. Consistent code rendering

Use the same language detection and syntax highlighting across the regular file editor, Changes mode, single-file diffs, and combined diffs.

2. Lightweight symbol context and navigation

Show the available symbol information through hover or the context menu:

• Symbol kind and signature
• Definition file and location
• References
• Inheritance relationships when a semantic provider can resolve them accurately

Provide familiar actions such as:

• Peek/Open Definition
• Find References
• Search in Files as a fallback

When semantic analysis is unavailable, Orca should fall back to workspace search instead of showing misleading or empty results.

3. Structural folding

• Fold functions, classes, imports, comments, and other scopes
• Provide Fold, Unfold, and Fold All commands
• Preserve fold state across file switches where practical

Diff views should never hide changed code without an indicator. If a folded region contains changes, it should be clearly marked, and hunk navigation should automatically reveal it.

Implementation direction

A lightweight, progressive approach seems appropriate:

1. Monaco-based syntax highlighting and folding
2. Lazy or on-demand Tree-sitter structural navigation
3. Optional semantic providers only for languages that need greater accuracy

Providers should start only when a capability is requested and should not index the entire repository during application startup.

Rather than introducing more separate implementations, I suggest consolidating the related work in #5247, #5595, #8574, #961, and #4654 behind a shared capability/provider contract.

Out of scope

• Embedding another editor
• A VS Code extension host
• Always-running language servers
• Diagnostics, autocomplete, or debugging in the initial scope
• Presenting heuristic results as accurate semantic results

This direction would preserve Orca's focus on agent orchestration and code review while reducing the need to open an external IDE for routine code comprehension.