Consider moving rules/constraints from procedures/ to knowledge/rules/

## Context
During implementation of #872, we created `knowledge/procedures/non-interactive-execution.md`. However, this raised a taxonomical question: is this really a procedure, or is it a rule/constraint?

## The Debate
- **Procedures** typically describe "how to do something" - actionable sequences
- **Rules/Constraints** describe "what cannot be done" or "what must always be true"
- The non-interactive execution doc describes a physical constraint: Claude literally cannot provide interactive input

## Proposal
Create a new `knowledge/rules/` directory for fundamental constraints that govern all interactions but aren't procedural in nature.

## Initial Candidates for Rules
- `non-interactive-execution.md` - Claude cannot provide interactive input to commands
- (future) Other hard constraints that shape what's possible vs impossible

## Implementation
Simple `git mv` operations - no content changes, just reorganizing our taxonomy.

## Testing Approach
Can verify the file is in Claude's context window using:
```bash
claude -p "echo 'What rules are in your knowledge base?'"
```

Related to: #872

Start by checking knowledge/procedures/non-interactive-execution.md and the existing knowledge layout. Move the file into the proposed knowledge/rules/ directory with git mv, preserving its content, then run the provided claude -p command to verify it remains in Claude's context window. Done means the taxonomy is reorganized without content changes.

Written by the indexing model from the issue text.