feat(cli): add --latest flag to show or convert latest conversation

[yanggthomas]

feat: Add --latest flag to show/convert latest conversation

Summary

Adds support for the --latest flag to quickly access the most recent conversation without TUI interaction.

Features

• cclog --latest - Outputs {sessionId}\t{title} of the most recent conversation
• cclog --latest -o - Converts latest conversation to markdown with auto-generated filename from title
• cclog --latest -o output.md - Converts latest conversation to specific output file
• Intelligent filename generation from conversation titles (supports CJK, English, special chars)
• Automatic filename collision detection (adds _1, _2 suffixes)

Changes

• Added --latest CLI flag handling in ParseArgs()
• Added Latest and AutoOutput config fields
• New functions: getLatestSessionInfo(), convertLatestToFile(), getUniqueFilename(), generateFilenameFromTitle(), sanitizeForFilename()
• Added GetSessionID() in usecase to extract session UUID from filename
• Fixed indentation (spaces→tabs) in multiple test files
• Enhanced help text with new examples

Testing

• Added comprehensive tests for all new functionality in command_test.go
• Test coverage includes: basic --latest, auto-output, filename generation, collision handling

Examples

# Get latest conversation UUID and title
cclog --latest
# Output: a1b2c3d4-e5f6-7890-abcd-ef1234567890	Deploy microservices architecture

# Auto-convert to markdown (auto-named from title)
cclog --latest -o
# Output: Output written to: Deploy_microservices.md

# Convert to specific file
cclog --latest -o my_conversation.md

Possible usage with claude code

// note/SKILL.md
---
name: note
description: Save current conversation to markdown file
disable-model-invocation: true
allowed-tools: Bash(cclog*)
argument-hint: [filename.md]
---

Save the current Claude Code conversation to a markdown file using cclog.

Run: `cclog --latest -o $ARGUMENTS`

- If no filename given: auto-generates from conversation title
- If file exists: adds counter suffix (_1, _2, etc.) to avoid overwriting