v0.2.0: cited MoS2 coefficient sets

Two cited coefficient sets for monolayer 1H-MoS2 ship with full provenance, and the test-suite reproduces the source paper's published separation results from them.

• mos2_a1_2la(): the A'1 + 2LA(M) pair of the source paper. Strain lever arms -5.1 and -20.9 cm^-1 per percent of biaxial strain (frozen-phonon DFT, ratio 4.1); A'1 doping coefficient -2.2 cm^-1 per 1e13 cm^-2 of electrons (Chakraborty et al., Phys. Rev. B 85, 161403(R) (2012)). The 2LA(M) doping coefficient is unmeasured and set to zero, with the source paper's 16% bound on the consequence documented.
• mos2_eprime_a1(): the all-optical E' + A'1 pair from the measured biaxial Grueneisen parameters of Michail et al., ACS Appl. Mater. Interfaces 16, 49602 (2024). For equal shift noise it returns about five times the strain uncertainty of the paper pair; included for comparison.
• New tests lock every number and reproduce the published results: edge charge 2.3e12 cm^-2 from a 0.5 cm^-1 A'1 redshift with 2LA(M) unmoved, and 0.134% interior tension carrying no significant charge. 13 tests total.
• FUNDING.yml added (Patreon sponsor button).

No API changes; v0.1 code continues to work unchanged.