[Feature] Refactor Mem0 instrumentation for OpenTelemetry GenAI Memory semantic conventions

## Background

LoongSuite currently instruments Mem0 with legacy custom `gen_ai.memory.*` fields and a broad method-to-operation mapping. The current semantic-convention alignment adds a minimal compatibility adapter, but it intentionally does not claim complete Mem0 support.

OpenTelemetry GenAI semantic conventions now define Memory operations and attributes, including:

- operations: `create_memory_store`, `search_memory`, `create_memory`, `update_memory`, `upsert_memory`, `delete_memory`, `delete_memory_store`
- `gen_ai.memory.store.id`
- `gen_ai.memory.record.id`
- `gen_ai.memory.record.count`
- opt-in `gen_ai.memory.query.text`
- opt-in `gen_ai.memory.records`

## Current minimal adapter

- `add` -> `upsert_memory`
- `update` / `batch_update` -> `update_memory`
- `search` / `get` / `get_all` / `history` -> `search_memory`
- `delete` / `batch_delete` / `delete_all` -> `delete_memory`
- local `Memory` / `AsyncMemory` operations use `INTERNAL`; remote `MemoryClient` / `AsyncMemoryClient` operations use `CLIENT`
- only explicit store and record identifiers are mapped
- query and record content are emitted only when content capture is enabled

This mapping is intentionally conservative. In particular, `delete_all` does not necessarily mean `delete_memory_store`, and framework-scoped `user_id` / `agent_id` / `run_id` values are not assumed to be OpenTelemetry memory-store identifiers.

## Required full redesign

- [ ] Build a supported API matrix for Mem0 1.x and 2.x, including sync/async local classes and hosted clients.
- [ ] Cover method signatures and `options=` / nested request objects without relying only on top-level keyword arguments.
- [ ] Define stable `gen_ai.memory.store.id` derivation rules for local and hosted Mem0. Do not repurpose user/session/agent identifiers without an explicit contract.
- [ ] Normalize add/search/get/batch responses to the upstream Memory record schema (`content` required; `id`, `metadata`, and `score` when available).
- [ ] Define exact operation mapping for create/update/upsert/delete/store lifecycle APIs, including bulk operations and `delete_all`.
- [ ] Preserve the PII/content boundary: query text and records remain opt-in and must not leak through custom attributes or events.
- [ ] Validate `INTERNAL` vs `CLIENT` span kind for every supported class and deployment mode.
- [ ] Redesign the optional internal vector/graph/retrieval/rerank spans so the hierarchy is useful and does not duplicate the public Memory operation.
- [ ] Add sync, async, streaming-if-applicable, error, batch, and concurrency/context-isolation tests.
- [ ] Test both the oldest and latest supported Mem0 versions in CI; use recorded or mocked fixtures where provider credentials are not available.
- [ ] Add Weaver validation against the current upstream GenAI Memory registry and update `loongsuite-semantic-conventions` with the upstream Memory fields and operation enums.
- [ ] Verify Robin synchronization and commercial metric suppression/augmentation behavior before release.

## Acceptance criteria

- No legacy LoongSuite-only Memory attributes are emitted by default.
- Every supported Mem0 API has a documented operation name, span kind, store-id rule, record normalization rule, and content-capture behavior.
- Unsupported or ambiguous APIs omit fields instead of fabricating identifiers or operation semantics.
- Focused tests and real emitted-span Weaver samples cover local/hosted, sync/async, success/error, and content-capture on/off paths.
- LoongSuite and Robin preserve the same trace semantic contract; commercial metrics remain owned by Robin and are not duplicated by the open-source adapter.

Start by locating the current Mem0 instrumentation adapter and the loongsuite-semantic-conventions integration, then map supported Mem0 1.x and 2.x APIs across local classes and hosted clients. Review existing instrumentation tests and CI fixtures before adding coverage for sync/async, batch, error, concurrency, and content-capture paths. Validate emitted spans with Weaver and confirm Robin synchronization and metric ownership before considering the redesign complete.

Written by the indexing model from the issue text.