chore: replace hardcoded DSMedia with generic Media in docs and templates

[smartwatermelon]

Problem

The NAS share name DSMedia (specific to the current TILSIT deployment) has leaked into documentation and templates where a generic default like Media should be used instead. The actual share name should come from NAS_SHARE_NAME in config/config.conf at runtime, not be hardcoded.

Scope

Search and replace DSMedia with Media across docs and templates. Verify each occurrence to distinguish between:

• Fix: hardcoded in docs/templates where a generic example or NAS_SHARE_NAME variable should be used
• Skip: runtime-generated files or config.conf itself (where the user's actual value belongs)

Quick audit

grep -r "DSMedia" --include="*.md" --include="*.sh" --include="*.template" .