fix(parser): split "and he/she <verb>" gendered-pronoun compound continuations

[davion-knight]

Fixes #5445.

Problem

A bare gendered pronoun ("he"/"she") used as an Oracle-text subject refers to the card itself (CR 109.3 + CR 201.4b). In a compound effect chain the clause-boundary splitter (starts_bare_and_clause_lower) recognized the singular anaphor it <verb> as a subject-predicate clause start but omitted the gendered pronouns, so a conjunct like Machine Man, Model X-51's

Whenever you cast a noncreature spell, put a +1/+1 counter on Machine Man and he gains flying until end of turn.

fell through to the imperative-only path and failed closed to Effect::Unimplemented { name: "he" }. (The ... and it gains flying ... form and the standalone he gains flying both already parse correctly.)

Fix

Add a composed ("he"|"she") × (gains|gets|has|loses|doesn't|can't|cannot) arm mirroring the singular it verb set — not the plural they arm, which excludes P/T get for its conditional-rider path. The split routes the conjunct through the subject-predicate parser, where parse_subject_application already maps "he"/"she" to SelfRef. Pronoun × verb are composed rather than enumerated per permutation (per the parser's combinator conventions).

Parser-only: no new engine type, variant, or runtime — the grant reuses the existing SelfRef continuous-modification path.

Verification

• Live parse (before → after): Machine Man's he gains flying conjunct goes from Unimplemented { name: "he" } → sub_ability granting AddKeyword(Flying) on SelfRef, UntilEndOfTurn — matching the it-form parse. she gains, he gets +1/+1, he loses … variants likewise resolve.
• No regressions: full-corpus parser-gap sweep is unchanged at 3977 unsupported cards. The new split only fires on and he/she <verb> boundaries, which previously always produced Unimplemented, so it cannot alter a currently-working parse.
• Test: added bare_and_clause_starts_on_gendered_pronoun_subjects next to the existing it/they boundary tests (positive verb-axis coverage + negative guards for non-continuous tails).
• cargo check -p engine + cargo fmt clean.

[gemini-code-assist]

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[github-actions]

Parse changes introduced by this PR · 1 card(s), 3 signature(s) (baseline: main e8244c78d4a9)

1 card(s) · ability/PutCounter · field duration: until end of turn → ∅

Examples: Machine Man, Model X-51

1 card(s) · ability/grant Flying · added: grant Flying (affects=self, duration=until end of turn, grants=grant Flying)

Examples: Machine Man, Model X-51

1 card(s) · ability/he · removed: he

Examples: Machine Man, Model X-51

1 card(s) had Oracle-text changes (errata/reprint) — excluded as non-parser.

[matthewevans]

Reviewed current head 5834b01: the parser split is at the existing subject-predicate boundary seam, composes the pronoun and verb axes, keeps negative guards for non-continuous clauses, and the current parse-diff is limited to Machine Man gaining the intended Flying grant while removing the stale duration from the counter effect.