Add read-only CLI for cached WhatsApp data

[Fr4nzz]

Summary

Adds a read-only whasapo cli command group for agents and scripts that prefer shell commands over direct MCP tool calls.

Commands added:

whasapo cli doctor --json
whasapo cli chats --json
whasapo cli search "family group" --limit 20 --json
whasapo cli messages --chat 120363xxx@g.us --limit 50 --json

The CLI reads the same local SQLite cache used by the MCP server and does not send messages.

Why a CLI in addition to MCP?

We ended up using a CLI wrapper in Codex Desktop because it was more reliable for read-heavy workflows:

• Some AI environments do not expose MCP tools consistently in every chat/session.
• Shell commands with JSON stdout are easy for agents to parse, log, retry, and test.
• Cached SQLite reads avoid opening competing MCP stdio streams for broad searches.
• Searches are fast and parallel-safe because they do not require a live WhatsApp connection.
• Agents can search broadly first, then inspect only the relevant chats/messages.

MCP is still the primary integration path for full interactive use and sending; this PR just adds a small terminal surface for cached read-only workflows.

Testing

• go test ./...
• go run ./cmd/whasapo cli help
• go run ./cmd/whasapo cli doctor --json
• go run ./cmd/whasapo cli search test --limit 2 --json