Bug: validate_migration.py truncates secret_id in diagnostic JSON output

[mrveiss]

Problem

autobot-infrastructure/autobot-backend/scripts/migrations/validate_migration.py truncates secret_id to 8 chars in the self.issues list, which is written to /tmp/migration_issues.json (line ~556). This diagnostic file is used to identify which secrets need attention during migration validation.

Truncated IDs make it difficult to identify specific secrets when investigating migration issues. The truncation was added in PR #2531 for log output (correct), but also applied to the data structure written to the diagnostic file (incorrect — this is an ops debugging tool, not a log).

Discovered During

Code review of PR #2531 (working on #2348 — clear-text logging)

Recommended Fix

Keep full secret_id in self.issues dict (data structure), truncate only in logger.* calls and user-facing report output.

Impact

Severity: low — affects migration debugging workflow only, not runtime behavior.

[mrveiss]

Merged in PR #2560. Full secret_id restored in diagnostic JSON output (4 data-structure locations); logger calls still truncated to 8 chars.