fix: missing exclude patterns + GPG signing crash

[FelixIsaac]

Problem

Two bugs causing real pain:

1. GPG signing crash on push
git.Commit() called git commit -m ... without overriding GPG signing. Any machine with commit.gpgsign=true globally (common on dev machines) crashes every push with gpg failed to sign the data.

2. Missing exclude patterns
Several directories/files were never excluded, causing them to be committed to the sync repo on every push:

Path	Why it's junk
backups/	Auto .claude.json snapshots by CC — redundant with claude.json.age already synced
cache/	CC update/summary cache, ephemeral
chrome/	Machine-specific Chrome native host bat file
daemon/	Machine-specific pipe key
session-env/	Per-invocation env snapshots — 14,000+ files on an active machine
temp/	Temporary files
mcp-needs-auth-cache.json	Ephemeral MCP auth state cache
scheduled_tasks.lock	Runtime lock file
.last-cleanup	Timestamp marker
*.lock	All lock files (also catches tasks/**/.lock)

Fix

• internal/config/config.go: Add missing patterns to DefaultExcludePatterns
• internal/git/git.go: Pass -c commit.gpgsign=false in Commit() so it works regardless of global git config

Test

# Verify GPG bypass works
git config --global commit.gpgsign true
claude-code-sync push  # should no longer crash

# Verify excludes (dry run)
claude-code-sync push --dry-run  # backups/, session-env/ etc should not appear