Add bulk operations for entries

[coreyleavitt]

Problem

Common operations require manual iteration:

• Delete all expired entries
• Move all entries matching criteria to a group
• Batch update fields across multiple entries

Proposal

Add convenience methods for bulk operations:

# Delete expired entries
deleted_count = db.delete_expired_entries()

# Bulk move
entries = db.find_entries(tags=['archive'])
db.bulk_move(entries, destination_group)

# Bulk update (maybe too magical?)
db.bulk_update(entries, icon_id='1')

Alternatively, a simpler approach:

# Just add delete_expired as a common case
db.delete_expired_entries(include_groups=False)

Considerations

• Should bulk operations auto-save history?
• Transaction semantics (all-or-nothing vs best-effort)?

Labels

enhancement