Add structured analysis categories to introspect command

[dreamer-coding]

Summary

Expand introspect to organize output into structured analysis categories.

Motivation

As more data points are added, output can become overwhelming. Structured grouping improves readability and usability.

Proposed Solution

Group output into categories such as metadata, content statistics, structure analysis, and anomalies.

Alternatives Considered

Flat output, which becomes harder to interpret as features grow.

Additional Context

Pairs well with structured output formats and improves both human and machine consumption.