Enhance .gitignore for sensitive data and private key protection

[Copilot]

Expands .gitignore patterns to prevent accidental commits of sensitive credentials, private keys, and blockchain wallet data.

Key Additions

Environment & Configuration

• All .env variations (.env.local, .env.*.local, .env.development.local, etc.)
• Local config overrides (**/config.local.*)

Cryptographic Material

• SSL/TLS certificates: *.crt, *.cer, *.csr, *.der
• Private keys: *.ppk, *.jks, *.keystore

Credentials & Secrets

• API keys: api-keys.json, *.secrets.json
• Service accounts: service-account*.json
• Cloud providers: .aws/config, .gcp/credentials, .azure/credentials, gcloud-service-key.json

Blockchain/Web3 (critical for this repo)

• Wallet files: keystore/, wallet.json, wallet.dat, *.wallet
• Seed material: mnemonic.txt, seed.txt, private-key.txt

Database & Backups

• Dumps: *.sql, *.sqlite, *.dump, *.backup

Organization

• Categorized into logical sections with comments
• Fixed formatting (removed tab before *.id_ed25519)
• Corrected Windows thumbnail pattern (ehthumbs_vista.db)
• Removed redundant generic *.log pattern in favor of specific patterns

Original prompt

Add.gitignore to hide sensitive data and private keys

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.