Fix redundant CD detection for SSH runtime

[ammar-agent]

Problem

The bash tool was not properly detecting redundant cd commands when using SSH runtime. The original code used path.resolve() which only works for local filesystem paths, causing it to fail when paths were on a remote SSH server.

Root Cause

path.resolve() is a Node.js API that only understands the local filesystem and can't normalize remote SSH paths correctly.

Solution

Delegate path normalization to the Runtime interface instead of having the bash tool understand different runtime types.

1. Added normalizePath() method to Runtime interface: Each runtime can handle its own path semantics
2. LocalRuntime implementation: Uses Node.js path.resolve() for local paths
3. SSHRuntime implementation: Uses POSIX path semantics (no filesystem access required)
4. Updated bash.ts: Simply delegates to config.runtime.normalizePath()

This maintains better separation of concerns - the bash tool doesn't need to know about SSH vs Local runtime specifics.

Test Coverage

Added 6 comprehensive tests specifically for SSH runtime:

• ✅ Redundant cd to absolute path (cd /home/user/project)
• ✅ Redundant cd with relative path (cd .)
• ✅ Redundant cd with tilde path (cd ~/project)
• ✅ Redundant cd with single tilde (cd ~)
• ✅ Trailing slashes in target path (cd /path/)
• ✅ Trailing slashes in cwd

All 52 tests pass (46 existing + 6 new)

Changes

• src/runtime/Runtime.ts: Added normalizePath() interface method (+19 lines)
• src/runtime/LocalRuntime.ts: Implemented for local paths (+10 lines)
• src/runtime/SSHRuntime.ts: Implemented for remote POSIX paths (+35 lines)
• src/services/tools/bash.ts: Simplified to delegate to runtime (-59 lines)
• src/services/tools/bash.test.ts: Added SSH runtime test suite (+136 lines)

Before vs After

Before (Broken)

# SSH Runtime with cwd = "/home/user/project"
Tool Call: bash("cd /home/user/project && ls")
Result: ✗ Would execute with redundant cd (not detected)
Final command: cd "/home/user/project" && cd /home/user/project && ls

After (Fixed)

# SSH Runtime with cwd = "/home/user/project"
Tool Call: bash("cd /home/user/project && ls")
Result: ✅ Error: "Redundant cd to working directory detected"

Benefits

• ✅ Consistent behavior between LocalRuntime and SSHRuntime
• ✅ Prevents redundant cd commands in SSH environment
• ✅ Better separation of concerns (runtime handles its own path logic)
• ✅ bash.ts is simpler and doesn't need runtime-specific knowledge
• ✅ No breaking changes to existing functionality