feat(reborn): add database capability lease stores

[serrrfirat]

Summary

• add feature-gated libSQL/Postgres CapabilityLeaseStore implementations
• persist scoped capability leases with owner/invocation/lease columns plus validated JSON payloads
• preserve lease lifecycle semantics for issue, revoke, claim, consume, scope listing, and active context lookup
• add libSQL contract tests for persistence, lifecycle mutation, and fingerprint claim guards

Verification

• cargo test -p ironclaw_authorization --features libsql --test db_capability_lease_store_contract
• cargo test -p ironclaw_authorization --features libsql
• cargo clippy -p ironclaw_authorization --features postgres --tests -- -D warnings
• cargo clippy -p ironclaw_authorization --features libsql,postgres --tests -- -D warnings

Stacked on #3349 because run-state/approval DB stores are the adjacent control-store slice.

Refs #3333, #3026, #3087

[gemini-code-assist]

Warning

You have reached your daily quota limit. Please wait up to 24 hours and I will start processing your requests again!