Implement Immutable SOAP Clinical Notes (Append-Only)

[devdeen213]

This PR introduces the initial implementation of immutable clinical notes for the LumenHealth EHR to ensure medical auditability. On the backend (apps/api/src/modules/notes), a ClinicalNoteModel is added with strict append-only behavior—PATCH and DELETE operations are intentionally unsupported and return 405 Method Not Allowed. Notes are created via POST using a temporary hardcoded encounterId: "mock-enc-123". A CORRECTION note type is also supported, allowing doctors to issue a new note that visually supersedes a previous entry without modifying the original. On the frontend (apps/web/src/components/notes), this PR adds a segmented SOAP (Subjective, Objective, Assessment, Plan) editor using markdown or rich text, along with a chronological Notes Feed displaying author badges and timestamps for each entry. The feed visually represents CORRECTION notes (e.g., striking through the superseded note and referencing the new one). Form submission clears the editor and optimistically updates the feed. The API enforces that notes cannot be updated or deleted under any circumstances, ensuring a permanent audit trail.

closes #115

[inteee]

Please block nested corrections: CORRECTION notes should not be allowed to target another CORRECTION note. Corrections must only reference original non-correction clinical notes to keep amendment chains clear and compliant.

[inteee]

Looks good to me. The changes are clear and well implemented. Approved.