feat: add a bunch more secret patterns

[ellie]

All of these secrets are invalid. Shush scanners and agents.

Checks

• I am happy for maintainers to push small adjustments to this PR, to speed up the review cycle
• I have checked that there are no existing pull requests for the same thing

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[greptile-apps]

Greptile Summary

Adds secret-detection patterns and negative tests for commands that must remain in history.

• Expands vendor token, credential URI, authorization header, Kubernetes, and environment-variable detection.
• Broadens Slack webhook ID lengths.
• Adds regression coverage for non-secret commands.

Confidence Score: 4/5

The ConfigMap false positive should be fixed before merging because it silently drops legitimate command history.

The default-enabled filter classifies every --from-literal command as secret-bearing even when Kubernetes uses it for a non-secret ConfigMap.

Files Needing Attention: crates/atuin-client/src/secrets.rs

Important Files Changed

Filename	Overview
crates/atuin-client/src/secrets.rs	The new patterns improve coverage, but the unscoped --from-literal regex also drops non-secret ConfigMap commands.

_{Reviews (1): Last reviewed commit: "feat: add a bunch more secret patterns" | Re-trigger Greptile}

[greptile-apps]

ConfigMap literals lose history

When kubectl create configmap ... --from-literal=... is used, this unscoped pattern classifies the non-secret command as secret-bearing, causing it to be silently omitted from history and removed by history pruning.

[taylordotfish]

maybe move this into the tests module if it's only used by tests?