feat: add safety tables, sync decision guide, goleak, and noCopy pattern

[gonzaloserrano]

• Low-cardinality error messages (don't interpolate IDs into error strings)
• Nil safety table (nil map/slice/channel behavior)
• Slice aliasing trap with full-slice expression fix
• Copy semantics quick reference table
• context.WithoutCancel for background work
• Sync primitive decision table (atomic vs mutex vs channel vs errgroup)
• noCopy sentinel pattern with go vet enforcement
• goleak goroutine leak detection in tests
• Extract security checklist to reference/security-checklist.md
• Compress AIP and security helpers sections

Bump version to 1.0.25

[cubic-dev-ai]

1 issue found across 6 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="skills/gopilot/SKILL.md">

<violation number="1" location="skills/gopilot/SKILL.md:36">
P2: The example contradicts the low-cardinality rule: it still interpolates `name` into the error string. Use a stable message without variable data.</violation>
</file>

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