[BUG] — `instance_info.selectByQuery`: fetches TEXT `instance_info` column + leading-wildcard LIKE + no pagination

- severity: Medium-High; files: `mappers/instance-info-sqlmap.xml:80-94`; service `InstanceInfoServiceImpl.java:81-84` (no `@Pageable`)
- description: `Base_Column_List` includes `instance_info` (TEXT NOT NULL, `schema.sql:1572` holding full instance metadata JSON); `instance_ip like CONCAT('%', #{instanceIp}, '%')`; table has only PK, no index on `namespace_id`/`instance_ip`/`instance_port`/`instance_type`.
- impact: List endpoint transfers N × TEXT payloads and scans the whole namespace partition.
- suggested_fix: Exclude `instance_info` from list VO; add index on `(namespace_id, instance_type)`; add `@Pageable`.
- confidence: High

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_Identified during the 2026-08-02 deep re-scan; full list in [`docs/scan2-2026-08-02/06-medium-tiers.md`](docs/scan2-2026-08-02/06-medium-tiers.md)._

Start with mappers/instance-info-sqlmap.xml:80-94 and InstanceInfoServiceImpl.java:81-84, then inspect schema.sql:1572 and the referenced list VO. Confirm how selectByQuery builds its result and pagination behavior. Done means the list avoids transferring instance_info, uses the proposed index and pageable handling, and preserves the endpoint’s intended results.

Written by the indexing model from the issue text.