docs(spec): fix Ligero parameters, constraints, and quadratic layout

[mtbadakhshan]

This PR is documentation-only plus comment fixes; no functional behavior is changed.

This PR corrects several inconsistencies in docs/specs/ligero.md relative to the implementation and the Ligero construction, primarily around row/column accounting, parameter definitions, and quadratic-row layout.

Changes:

A) In docs/specs/ligero.md

1. Define missing parameter:
   Define NW (total number of witnesses), which is used later in inner_product_vector.
2. Fix row-count formulas:

• Correct the number of rows used to encode witnesses and quadratic constraints:
  • NQW = NWROW + 3 * NQT,
• Correct the total number of rows in the witness matrix T:
  • NROW = NQW + 3 (three blinding rows are added to the witness matrix T).

3. Fix inconsistent constraints on parameters

• Remove redundant constraints:
  • BLOCK > NREQ (redundant given BLOCK = NREQ + WR).
• Remove mutually inconsistent inequalities involving BLOCK:BLOCK = NREQ + WR, BLOCK >= 2 * (NREQ + QR) + (NREQ + WR) - 2, BLOCK >= 2 * (NREQ + WR) - 1, and Replace them with the correct quadratic-row length constraint
  • DBLOCK = 2 * (NREQ + WR) - 1
• Explicitly state the number of tableau columns (denoted BLOCK_ENC in code):
  • NCOL = DBLOCK + ceil(BLOCK / rate)

4. Fix undefined identifier

• Replace the undefined identifier Q with QR in the layout_quadratic_rows pseudocode.

5. Fix quadratic row layout

• Correct the row indexing in layout_quadratic_rows to match the intended layout:
  • all x rows first, followed by all y rows, then all z rows.
  • This matches both ligero_param.h and the triple-row structure described in the Ligero paper.

6. Fix inner-product vector layout

• Correct the coefficient-vector sizing text in inner_product_vector.
• Update the offsets (a_x, a_y, a_z) to reflect the corrected row layout and dimensions.

B) In lib/ligero/ligero_param.h

7. Fix misleading comment

• Correct the comment describing nwqrow:
  • nwqrow = nwrow + 3 * nqtriples;

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