feat: redact sensitive flags in logging middleware

[nborges-aws]

Description

Added sensitive option to flag() API to prevent identity credentials from being persisted to bug logs (ref: #1811). The withLogging middleware will now redact any flag with sensitive field set to true before logging.

Changes:

• src/router/handler.tsx — Added sensitive?: boolean to the Flag interface; changed flag() 4th param from help?: string to options?: { help?: string; sensitive?: boolean }
• src/middleware/withLogging.tsx — Added redactSensitiveFlags() which replaces sensitive values with [REDACTED]
• src/middleware/withLogging.test.ts — Added test verifying sensitive flags are redacted while others remain visible
• src/handlers/harness/{create,update}/index.tsx — Migrated existing help string args to { help: ... } format
• src/router/router.test.ts — Migrated help string to new format

I will update my identity PR to mark --api-key as { sensitive: true } after this is merged.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Other (please describe):

Testing

How have you tested the change?

• I ran npm run test:unit and npm run test:integ
• I ran npm run typecheck
• I ran npm run lint
• If I modified src/assets/, I ran npm run test:update-snapshots and committed the updated snapshots

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature, or no new docs are needed
• My changes generate no new warnings
• Any dependent changes have been merged and published

---

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terms of your choice.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.93%. Comparing base (56f62e7) to head (ecf537f).

Additional details and impacted files

@@             Coverage Diff              @@
##           refactor    #1814      +/-   ##
============================================
- Coverage     93.94%   93.93%   -0.02%     
============================================
  Files           122      122              
  Lines          6462     6445      -17     
============================================
- Hits           6071     6054      -17     
  Misses          391      391              

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[AlexanderRichey]

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[aidandaly24]

lgtm, this will be helpful