Fill in missing requirements rationale

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I reviewed the README file to see if the feature is in the major future work.
• I performed a cursory search to see if the feature request is relevant, not redundant, nor in conflict with other tickets.

Is your feature request related to a problem? Please describe.
The following requirements have empty rationale:
SC2000.3, SC2002.2, SC2005.1, SC2007, SC2007.1, SC2008, SC2008.1, SC2008.2, SC2008.3, SC2008.4, SC2008.5, SC2008.6, SC2008.7, SC2009, SC3000, SC3001.1, SC3003, SC3003.2, SC3003.2.1, SC3003.3, SC4001.1, SC4001.3.1, SC4003, SC4004, SC4005

Or use query: project = GSFCCFS AND issuetype = Requirement AND status in (Approved, Submitted) AND component in ("CF", CFS_LIB, CS, DS, FM, fs_lib, HK, HS, LC, MD, MM, SC) and "Requirement Rationale" is EMPTY ORDER BY cf[13194] ASC

Describe the solution you'd like
Fill in missing rationale

Describe alternatives you've considered
None

Additional context
None

Requester Info
Jacob Hageman - NASA/GSFC

Start by locating requirements SC2000.3 through SC4005 and reviewing each requirement's existing text and surrounding context. Done means every listed requirement has a substantive, reviewed rationale rather than an empty field; the issue provides no file or test path.