Split ingestion validation and materialization modules

[yvette-carlisle]

Summary

• Split add_note validation non-English traversal into a private validation/non_english module with child-module tests.
• Split add_note materialization into ADD, UPDATE, and NONE owner modules behind the existing materialize facade.
• Split add_event materialization into ADD, UPDATE, and NONE owner modules behind the existing persist_extracted_note_decision facade.

This PR batches three locally verified modularization commits so remote CI runs once for the group.

Validation

Commit: Split add_note validation non-English traversal

• cargo make fmt-rust
• cargo test -p elf-service add_note --lib (8 passed)
• cargo check -p elf-service --all-targets --all-features
• cargo nextest run -p elf-service --lib --all-features add_note (8 passed, 141 skipped)
• cargo make lint-vstyle
• cargo make lint-rust
• cargo make fmt-rust-check
• git diff --check
• cargo make check-rust
• cargo make test-rust (399 passed, 92 skipped)
• cargo make check (399 passed, 92 skipped)
• Skeptic gate passed with no blockers or material risks.

Commit: Split add_note materialization paths

• cargo make fmt-rust
• cargo test -p elf-service add_note --lib (10 passed)
• cargo check -p elf-service --all-targets --all-features
• cargo nextest run -p elf-service --lib --all-features add_note (10 passed, 141 skipped)
• cargo make lint-vstyle
• cargo make lint-rust
• cargo make fmt-rust-check
• git diff --check
• cargo make check-rust
• cargo make test-rust (401 passed, 92 skipped)
• cargo make check (401 passed, 92 skipped)
• Skeptic gate passed with no blockers.

Commit: Split add_event materialization paths

• cargo make fmt-rust
• cargo test -p elf-service add_event --lib (3 passed)
• cargo check -p elf-service --all-targets --all-features
• cargo nextest run -p elf-service --lib --all-features add_event (3 passed, 150 skipped)
• cargo make lint-vstyle
• cargo make lint-rust
• cargo make fmt-rust-check
• git diff --check
• cargo make check-rust
• cargo make test-rust (403 passed, 92 skipped)
• cargo make check (403 passed, 92 skipped)
• Skeptic gate passed with no blockers, material risks, or missing validation.