Render all-caps 2-letter credential initials as all-caps (0.4.2)

[atalyaalon]

@sergeyf — one small, final nit on top of the credential fix. Rendering only (no parse change), so it's low-risk; opening it separately so it's easy to review.

What & why

In 0.4.1 the credential fix recovered the surname for all-caps credential-collision initials (MS/MA/MD/…), but the given got re-cased to Title-case (MS Rahman → given Ms), so a kept initials token looked identical to the dropped Ms. honorific. This keeps a 2-letter all-caps given/middle token all-caps, so initials stay initials and no longer collide visually with the honorific.

Casing is (and stays) the discriminator — nothing about the drop logic changes:

• all-caps MS Rahman = initials → kept (0.4.1 rendered Ms; 0.4.2 renders MS).
• Title-case Ms Rahman = honorific → dropped (unchanged in both).

So MS Rahman (all-caps) and Ms Rahman (Title-case) are different inputs — 0.4.1 happened to render the kept one as Ms, which is the confusing collision this PR removes.

One-line change in _canonicalize_token (drop the not is_ambiguous_credential exclusion from the 2-letter all-caps branch) + test updates + version bump to 0.4.2.

0.4.0 → 0.4.1 → 0.4.2 by use case (given / middle / surname)

1. Leading initials + surname (the common case). 0.4.0 dropped the leading token and left an empty surname; 0.4.1 recovered the surname but title-cased the initials; 0.4.2 keeps them all-caps.

input	0.4.0	0.4.1	0.4.2
MS Rahman	Rahman / — / — (empty surname)	Ms / — / Rahman	MS / — / Rahman
MA Hassan	Ma / — / Hassan	Ma / — / Hassan	MA / — / Hassan
MD Ohman	Ohman / — / —	Md / — / Ohman	MD / — / Ohman
JD Baum	Jd / — / Baum	Jd / — / Baum	JD / — / Baum

2. Middle-position / non-leading initials. Same rendering fix, mid-name.

input	0.4.1	0.4.2
Miranda MA Whitten	Miranda / Ma / Whitten	Miranda / MA / Whitten
Sita MA Bierma-Zeinstra	Sita / Ma / Bierma-Zeinstra	Sita / MA / Bierma-Zeinstra
John MS Bartlett	John / Ms / Bartlett	John / MS / Bartlett
Gérard MD Ducable	Gérard / Md / Ducable	Gérard / MD / Ducable

3. Genuine honorifics — still dropped (unchanged). Casing is the signal: all-caps = initials (kept), Title-case = honorific (dropped).

input	0.4.1	0.4.2
Ms Rahman	— / — / Rahman (Ms dropped)	— / — / Rahman (unchanged)
Ms. Subbulakshmi	— / — / Subbulakshmi	— / — / Subbulakshmi
Dr Watson	— / — / Watson	— / — / Watson

4. Degrees — still dropped (unchanged). Trailing/mixed-case degree forms are unaffected.

input	0.4.1	0.4.2
Jane Doe EdD	Jane / — / Doe (EdD dropped)	unchanged
Robert Jones MD	Robert / — / Jones (MD dropped)	unchanged

Verification

Ran both 0.4.1 and 0.4.2 on the complete affected population — every corpus name containing an all-caps 2-letter credential token in any position (leading, middle, comma-form): 247,855 names.

• 31,628 changed — 100% rendering-only (code-checked: identical tokens in identical slots, differing only by letter case), 0 regressions (no surname / order / accept-reject change vs 0.4.1).
• Split: 22,718 leading (given) + 8,910 non-leading (middle/comma).
• Real people are the bulk (MS Rahman = 89 papers with all-initials co-authors; Miranda MA Whitten, John MS Bartlett, …). The set also contains messy multi-credential affiliation strings (MBBS MS FRACS Winy Widjaja) where the rendering is cosmetically applied but the string is junk regardless — a separate reject gap, unchanged here.

Tests: added/updated cases for the all-caps rendering; full suite unchanged otherwise (only the pre-existing Chinese-routing failures remain, 0 new). ruff clean.