[docs] Document inventory filtering and exclusion behaviors

[paul-fresquet]

Summary

Document the file filtering and exclusion behaviors in ByteSync, explaining what types of entries are excluded, why, and on which platforms.

Background

ByteSync filters various filesystem entries during inventory building. This behavior should be documented for:

• End users who want to understand why files don't appear
• Contributors who need to understand the filtering logic
• Future maintainers

Proposed Documentation

Create or update documentation covering:

1. Entry Types and Handling

Entry Type	Behavior	Platforms	User Configurable
Regular files	Included	All	No
Directories	Traversed	All	No
Symbolic links	Excluded	All	No
Block devices	Excluded	Linux/macOS	No
Character devices	Excluded	Linux/macOS	No
FIFOs	Excluded	Linux/macOS	No
Unix sockets	Excluded	Linux/macOS	No
Hidden files	Excluded (optional)	All	Yes
Noise files	Excluded (optional)	All	Yes

2. Noise Files List

Document all files in the noise list with their platform and purpose.

3. Protected Paths

Document paths that cannot be used as data sources (/dev, /proc, etc.).

4. Platform-Specific Behaviors

• Windows: FileAttributes.System, FileAttributes.Offline, ReparsePoint
• macOS: Dot-files as hidden, resource forks
• Linux: Dot-files as hidden, special filesystems

Proposed Location

Option A: docs/inventory-filtering.md (new file)
Option B: Section in existing README.md
Option C: Section in docs/synchronization-rules.md

Acceptance Criteria

• Document all entry types and their handling
• List all noise files with explanations
• Explain protected paths
• Document platform-specific behaviors
• Include examples where helpful
• Keep documentation in sync with code (add note about maintenance)

Content Outline

# Inventory Filtering and Exclusions

## Overview
ByteSync filters certain filesystem entries during inventory...

## Entry Classification
### Regular Files
### Directories  
### Symbolic Links
### POSIX Special Files

## Noise Files
### Windows
### macOS
### Linux

## Protected Paths

## Platform-Specific Behavior
### Windows
### macOS
### Linux

## User Settings
- Exclude hidden files
- Exclude system/noise files

Priority

Nice to Have — Improves user understanding and maintainability.