Post-release: allow CLI extraction safety limits to be overridden #331

Add explicit CLI overrides for extraction safety limits after the 0.5 release.

The CLI currently constructs ExtractPolicy with defaults of 1 GiB per file, 10 GiB total file bytes and 100,000 selected entries (including directories and symlinks). It exposes boolean overwrite/symlink/permission options but no numeric overrides. Rust API callers can supply a policy. Consequently the CLI can create an archive whose contents it refuses to extract under its defaults.

Scope and acceptance:

• Expose per-file bytes, total extracted bytes and selected-entry limits on applicable CLI extraction commands, mapping directly to the existing policy. Choose clear names and documented byte units.
• Preserve existing defaults when options are omitted. Require explicit user input to raise them; do not silently disable safeguards.
• Define and test handling of zero, malformed values, overflow, conflicting inputs and any supported unlimited setting; reject invalid values clearly.
• Keep path traversal, signature/authentication, symlink, overwrite and permission protections independent of numeric overrides. No archive-format change is needed.
• Add public CLI lifecycle tests: create/import through the CLI, demonstrate a deliberately lowered limit refuses extraction, raise it and extract successfully, then independently verify persisted bytes and applicable modes. Cover each limit including directory/symlink counting and boundary behavior without multi-gigabyte test fixtures.
• Update CLI help and manual archive-limit/file-operation guidance with examples and explanations of policy versus format limits.

This is post-release work; do not delay the current release or restart optimisation to implement it.