feat: --from-probe (mcp-probe → simulation handoff)

[MarouaBoud]

Summary

Adds stampede run --from-probe <descriptor.json> (FR-CLI-07) — take an mcp-probe result and turn it straight into a behavioural simulation. mcp-probe already knows how to reach a server; --from-probe reads its JSON descriptor and builds the MCPTarget config, so a CI probe flows directly into a full swarm run.

How it works

• targets/from_probe.py maps a swarmproof.dev/probe/v1 descriptor (a {transport, command|url} block, nested or flat) to a TargetConfig.
• --from-probe PATH sets the target (no stampede.yaml required, like --target). Additive — no existing behaviour changed.

stampede run --dry-run --from-probe examples/probe.json

Verified

• Unit tests cover stdio/http/flat descriptors and the error cases (missing command/url, bad transport).
• A guarded e2e drives the real echo MCP server through a probe descriptor; confirmed via the CLI end-to-end (grade + misuse map produced).
• ruff + mypy clean; 80 tests pass. Based on main, independent.