A subprogram whose declined draws outnumber its trials fails by name; a dummy handed to what might write it is not read-only - #33

Closes rows 12, 13 and 14 of #32 -- the three that were on main, from #30.

Declined draws are bounded and repeated (rows 12, 13). differential.bitexact declines a draw the candidate stops or overruns on (SystemExit, IndexError) and one both sides take to NaN, and draws again. It did so up to 24 times a trial, counted the redraws in a per-subprogram metric nothing repeated, and passed once one draw survived: a translation that stopped on inputs the source accepts passed on the survivors. Now:

• a subprogram whose declined draws outnumber the trials it was compared on fails by name, with the count, the reason of each decline (error stop, subscript past extent, NaN on both sides) and the remedy (ranges, or dims). The reshaped rule, which names the extent, still speaks first.
• a passing verdict repeats the declined count and reasons in its detail; per-subprogram metrics carry declined by reason beside redrawn.

The whole-trial NaN redraw is kept -- what both sides do after a NaN is the compiler's scheduling -- but it is now counted against the same bound and said aloud.

Read-only is proved, not assumed (row 14). _infer_read_only_intents took a parenthesised reference whose base is not one of this file's subprograms for a subscript, and never walked a function reference, an internal WRITE or an ASSOCIATE; a dummy modified through a use-associated function, which parses exactly like a subscript, was inferred intent(in), dropped from the wrapper's outputs and compared on neither side. The pass now knows the scope's variables (dummies, locals, local parameters, module state): a base it does not name is a call whose variable actuals escape, an expression actual is a temporary and does not, the WRITE unit and the ASSOCIATE selector escape. What cannot be proved read-only stays UNKNOWN, and the gate refuses the routine by name, as before #30.

Held to: full suite (916), mypy, ruff green. Corpus re-run: no unit moves (31/67 mechanical, 433 deferred); minpack's chkder is now named in its unit's detail (19 draws declined, 19 error stop, against 10 trials -- mode takes two of the eight default integer values), a unit already failed on dogleg's moved extents. The intent tightening moves nothing in the corpus.

Tests: the redraw tests now assert the reason and the verdict's mention of it; two new ones hold the bound for an error stop and for NaN; one new interface test holds each escape (function actual, internal WRITE, ASSOCIATE) and each non-escape (array subscript, expression actual).

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https://claude.ai/code/session_01HYzzevwvTuLBMYjzdHUhGg