Add end-of-run summary output to `logira run`

[melonattacker]

Is your feature request related to a problem? Please describe.

Currently, after running a command with:

logira run -- <command>

users need to manually inspect the run using commands like:

logira view <run-id>
logira explain <run-id>

to understand what happened.

This creates friction for common cases where users only want a quick answer to questions like:

• How many events happened?
• Were any detections triggered?
• Which run should I inspect next?

Without a concise summary, users must always perform additional commands to determine whether anything noteworthy occurred.

Describe the solution you'd like

Display a concise summary automatically when logira run finishes.

Example:

[logira] run 20260314-153022-claude finished (2m34s)
  events: 47 exec, 123 file, 18 net
  detections: 2 found
    - credential-read: ~/.aws/credentials (1 event)
    - suspicious-exec: curl | sh pattern (1 event)

  → logira view 20260314-153022-claude

The summary should include:

• run ID
• run duration
• event counts by category (exec / file / net)
• detection count
• a small list of top detections
• a hint for the next command (logira view)

Describe alternatives you've considered

Users can currently inspect runs using:

logira view
logira explain
logira query

However, these require additional manual steps and are inconvenient for quick inspection.

Another option would be a full TUI interface, but that would be a much larger change. A simple summary would already reduce friction significantly.

Additional context

This aligns well with logira's design as an observe-only auditing tool.
The summary would not replace existing review commands but would provide a quick overview to help users decide whether deeper inspection is necessary.