Fix live-converge word casing: stuck all-caps (#4) + dropped auto-cap (#5)

[SHAWNERZZ]

Fixes two casing bugs specific to the live-converge (#1.7) merged-trail re-recognition. Both are gated to that path, so a plain single gesture — including an intentional standalone acronym swipe — is untouched.

#4 — word gets stuck in all-caps

A short, ambiguous swipe can make the glide recognizer's top pick an all-caps dictionary acronym (e.g. CSA), while the keyboard is unshifted. That sets WordComposer.isAllUpperCase, which makes Suggest.getSuggestedWordsForBatchInput force every later candidate to all-caps; live-converge then keeps replacing the word with the uppercased result, so it stays stuck (CSA → CAN → CAME, suggestions shown in caps) until the word is committed. Confirmed from a debug log — there is no setShiftLocked=true, so it isn't a caps-lock/Shift-key bug.

#5 — extending a word drops the auto-capital

The first-letter capital comes from mShiftModeAtGestureStart, captured at gesture start and cleared after the first commit. A live-converge extending tap re-recognizes the whole word and re-commits with that value already OFF, so Hello becomes hellow.

Fix

In InputLogic.onUpdateTailBatchInputCompleted, when usedMergedTrail is set, re-derive the case from the word being re-recognized:

• CAPITALIZE_FIRST → re-apply the leading capital (fixes Live-converge: extending a word drops the auto-capitalized first letter #5 — capital survives every re-converge);
• CAPITALIZE_ALL → lowercase it unless the keyboard is genuinely shift-locked (fixes Live-converge: word gets stuck in all-caps after recognizer returns an acronym #4 — stops the isAllUpperCase latch at the source; deliberate caps-lock still works).

Trade-off: gliding an acronym and then extending it normalizes to lowercase. A standalone acronym swipe (no extension) is unaffected.

Testing

• :app:compileStandardDebugJavaWithJavac clean on this base (off main).
• InputLogicTest.extendBase* (live-converge/merged-trail regression) green on the source branch.

Fixes #4
Fixes #5

[SHAWNERZZ]

Force-pushed a refined implementation (replaces the earlier prior-word heuristic).

Why the change: the prior-word approach mis-fired on a sentence-start acronym (Can→can) and regressed swipe-extension casing (Was+swipe→wait). It also coupled three separate concerns into one inferred value.

New approach: separate a word's casing intent from the recognizer's letters.

• WordComposer.mCapitalizedMode is the persistent per-word intent (survives the setBatchInputWord rebuild, cleared at commitWord); exposed via getCapitalizedMode().
• InputLogic.applyComposingCase(lemma, capsMode, locale) lowercases the recognizer output then re-applies the intent — lowercasing first dissolves the all-caps latch (Live-converge: word gets stuck in all-caps after recognizer returns an acronym #4) at the source.
• onStartBatchInput captures intent only for a fresh word, so an extending gesture preserves the first fragment's intent (Live-converge: extending a word drops the auto-capitalized first letter #5 / the Wait case).
• Fresh-word gesture capitalization is unchanged, so plain glide typing is byte-identical and a standalone acronym swipe still stays as-is.

Unit-tested directly (applyComposingCase is pure) plus intent-lifecycle tests; suite green except the 3 documented pre-existing failures. Validated on-device.