fix(inspect): Docker discovery bugs - broken find, N+1 perf, OOM risk, wrong size units

[CodeMonkeyCybersecurity]

Summary

Multiple bugs and performance issues in pkg/inspect/docker.go:

1. P0 Bug: discoverComposeFiles() passes 2>/dev/null as a literal argument to find (via exec.Command, which doesn't interpret shell redirections). Also, -type f is ungrouped and only applies to the last -name pattern.
2. P0 Perf: discoverContainers() runs N+1 shell commands (1 docker ps + N docker inspect). On 50 containers, this is ~15s of unnecessary latency.
3. P1 Security: os.ReadFile on discovered compose files has no size limit - a symlink to a multi-GB file causes OOM.
4. P1 Correctness: parseHumanSize uses binary multipliers (1024) but Docker uses SI/decimal (1000). 1GB returns 1073741824 instead of 1000000000.
5. P1 Style: Emoji characters in log messages despite commit 9cd58733 removing them.

Root Cause

• exec.Command API misunderstanding (shell syntax in non-shell context)
• No batching strategy for Docker CLI calls
• Missing input validation on file reads
• Incorrect unit conversion assumption
• Incomplete emoji sweep

Fix

See PR for implementation.