fix(editor): normalize paths in content cache to prevent duplicate entries

[Ashutosh0x]

Issue

Fixes #345

Description

The editor tool's CONTENT_HISTORY cache uses raw path strings as dictionary keys. When the same file is referenced via different path formats, separate cache entries are created:

`python

These all point to the same file but create different cache entries:

editor(command='view', path='./file.py')
editor(command='view', path='/absolute/path/file.py')
editor(command='view', path='~/project/file.py')
``n
This causes:

• Stale cache reads (editing via one path doesn't invalidate the other)
• Unnecessary file I/O (cache misses for already-cached files)
• Potential data inconsistency between cache and disk

Fix

Apply os.path.normpath(os.path.abspath(...)) after os.path.expanduser() at the entry point of the editor function (line 317). This ensures all path variants resolve to the same canonical absolute path before being used as cache keys.

`python

Before:

path = os.path.expanduser(path)

After:

path = os.path.normpath(os.path.abspath(os.path.expanduser(path)))
``n
This is a single-line, minimal-risk fix that normalizes the path once at the top of the function, so all downstream operations (cache reads, cache writes, file operations, backup paths) use the same canonical path.

Testing

• Verified that os.path.normpath(os.path.abspath('./file.py')) and os.path.normpath(os.path.abspath('/full/path/file.py')) produce identical results
• No behavior change for existing absolute paths (normpath of an already-absolute path is the same path)
• Tilde expansion still works (expanduser runs first)