Remove deprecated backward-compatibility methods in CacheDBInterface

[Vasilije1990]

Problem / Background

The CacheDBInterface in cognee/infrastructure/databases/cache/cache_db_interface.py contains three deprecated backward-compatibility methods with explicit :TODO: delete comments:

• add_qa() (delegates to newer method)
• get_latest_qa() (delegates to newer method)
• get_all_qas() (delegates to newer method)

These methods add confusion and maintenance burden. The TODO comments indicate the maintainers intended to remove them.

Goal

Remove the deprecated methods and update any remaining callers to use the new API directly.

Proposed Solution

1. Search for all callers of add_qa, get_latest_qa, get_all_qas:

rg "add_qa|get_latest_qa|get_all_qas" cognee/ --type py

2. Update any callers to use the replacement methods
3. Remove the deprecated methods from the interface and all implementations (RedisAdapter, FSCacheAdapter)

Acceptance Criteria

• All three deprecated methods are removed from CacheDBInterface
• All implementations (Redis, FS) are updated
• All callers are migrated to the new API
• Existing tests pass
• ruff check . passes

Dependencies / Blockers

None — the TODO comments indicate this was already planned.

Relevant Links / Resources

• File: cognee/infrastructure/databases/cache/cache_db_interface.py (lines ~56, ~87, ~98)

[coderabbitai]

🔗 Related PRs

#1430 - Feature/cog 2979 fix falkordb adapter [merged]
#2077 - feat: Adds CRUD operations to CacheAdapters and implements initial SessionManager (part 1: Adapter level) [merged]
#2082 - feat: Adds CRUD operations to CacheAdapters and implements initial SessionManager (part 2: Session Manager) [merged]

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[JiwaniZakir]

Happy to tackle this one. Working on it.

[JiwaniZakir]

Submitted a PR: #2332