MCA (E): route denominator-root and coordinate-clone exceptions

[AllenGrahamHart]

What changed

This advances two named branches of the paper's MCA exception-routing
terminal (E).

Denominator-root branch

• Proves an exhaustive post-cancellation split: a support either remains
  support-wise MCA-nontrivial in the reduced certificate, or has a unique
  simultaneous explaining pair.
• In the trivialized branch, compiles the original obstruction into a
  same-owner pole-defect record
  u_i + gamma_i v_i = 0 with v_i != 0; the slope is recoverable and
  distinct slopes have distinct explaining pairs.
• Proves distinct trivialized reduced supports intersect in at most k-1
  coordinates and therefore have disjoint k-shadows.
• Prints an exact route fence: the resulting shadow-packing upper bound is
  larger than 2^58 throughout both deployed pole-degree ranges, so it does
  not pay either row. Further support-only packing cannot close (E) through
  this bound; the remaining target must use the coupled divided
  scalar-locator identity.

The packet preserves the precise cancellation scope: Q' is nonzero on the
reduced coincidence core, not necessarily on the whole reduced domain.

Coordinate-clone branch

• Pays every irreducible owner-pencil clone class of size 2 <= c < m by
  N_C(m-c) <= 2(n-c) <= 2c(m-c).
• Sums all subcritical classes through their disjoint coordinate mass to get
  the literal simultaneous bound 2n = 4,194,304, below both MCA budgets.
• Uses n < 2m to prove that at most one class of size at least m remains.
• Keeps identically-zero/fixed-owner coordinates and the unique large clone
  component explicit and unpaid.
• Records a source-contract no-go for the remaining class: F_x=0 is an
  owner-line incidence, not a selected-support root. The scalar-locator term
  remains, so clone zeros and denominator-root sets cannot be injected into
  actual agreement supports without also proving Lambda(x)=0.

Source-pin repair

The existing pole-tolerant verifier on current main failed because its
grande_finale.tex blob pin predated later paper integrations. This PR
refreshes that pin to the current blob. The pinned scalar-locator definition
is byte-for-byte identical to the formerly pinned definition; no audited
theorem scope is changed.

Validation

All commands pass under both normal Python and python3 -O:

verify_pole_tolerant_scalar_locator_localization.py --check
verify_pole_tolerant_scalar_locator_localization.py --tamper-selftest
verify_denominator_root_puncture_trivialization.py --check
verify_denominator_root_puncture_trivialization.py --tamper-selftest
verify_coordinate_clone_subcritical_payment.py --check
verify_coordinate_clone_subcritical_payment.py --tamper-selftest

The two new checkers run 137,341 and 15,215 deterministic checks respectively;
each rejects 5/5 hostile metadata mutations. They use only the Python
standard library.

Nonclaims

These are local source compilers and route cuts. They do not bound the actual
trivialized-slope cardinality below the row budgets, pay the unique large
clone/fixed-owner branch, absorb every record into (S) or (A), prove
complete (E), close an adjacent row, or move the official score. Independent
review is explicitly requested in both packets.

[AllenGrahamHart]

Independent continuation of this PR's unique-large-clone frontier is now banked at 67d17fff8.

For a common irreducible clone component
F_*(gamma,tau)=a+b gamma+c tau+d gamma tau, ad-bc != 0, the Mobius parameterization gives the exact pullback

Qhat=(c+d gamma)Q_0-(a+b gamma)Q_1,
Nhat=(c+d gamma)(A_0+gamma B_0)
     -(a+b gamma)(A_1+gamma B_1),

with slope degrees (1,2) and Nhat=Qhat(r_0+gamma r_1) on every clone coordinate.

Two consequences are proved.

1. If the two denominator coefficients span one polynomial direction, every clone of size at least m+1 cancels to one fixed coherent rational owner (or the globally affine degeneration), apart from the single denominator-zero projective parameter. At exactly c=m, the only noncancelling remainder is mu Lambda_C.
2. In denominator rank two, writing Qhat=q_0+gamma q_1 and Nhat=p_0+gamma p_1+gamma^2p_2, the exact Pade remainder

Omega=q_1^2 p_0-q_0 q_1 p_1+q_0^2 p_2

vanishes on the clone and has degree at most m+2d. Hence c>m+2d forces one fixed affine-in-slope owner with reduced denominator degree at most 2d; at equality, Omega is zero or mu Lambda_C. The genuinely moving support bands end at 1,250,992 on KoalaBear and 1,250,920 on Mersenne-31.

This does not complete (E): the finite moving band, the exact locator remainders, and the fixed degree-(d,2d] owner remain unpaid. It does remove the arbitrary rank-one supercritical clone and turns the rank-two branch into those exact leaves. Four independent constant-memory checks pass, together with the local DAG/provenance gates.