docs: fix malformed floor table in merkle-agi-v8-consensus

The simple-table (=== separators) had a wrapped multi-line cell that
docutils rejected as malformed -> the floor table rendered broken on the
live site. Converted to a list-table (alignment-proof). Also switched the
proposer-submission block from 'code-block:: json' to 'text' — it's a
schema with <...> placeholders, not valid JSON, so the json lexer warned.
Page now builds with no errors/warnings on these blocks.

docs/_source/merkle-agi-v8-consensus.rst

@@ -287,7 +287,7 @@ Part 4 — Acceptance protocol
 
 A proposer (any actor — does not need to be a validator) submits:
 
-.. code-block:: json
+.. code-block:: text
 
    {
      "candidate_root":            "<C(M') SHA-256>",
@@ -311,17 +311,24 @@ clear a **canonical floor** before validators are obligated to
 audit. The canonical floor is published in the v8 substrate paper
 and pinned in ``consensus_policy_hash``:
 
-================================  ====================================
-Floor metric                      Threshold
-================================  ====================================
-``Δ5S`` (5-syndrome battery)      ≥ 0 (no regression)
-``Δ5T`` (5-transfer battery)      ≥ 0 (no regression)
-``Δ5F`` (5-falsification battery) ≥ 0 (no regression)
-ε-coverage at published frontiers ≥ floor specified per-frontier
-``audit_completeness``            = 1.0 (every state-change row hashes
-                                  through ``audit_events``)
-``hard_regression_flag``          = false (no ScoredFork hard regress)
-================================  ====================================
+.. list-table::
+   :header-rows: 1
+   :widths: 42 58
+
+   * - Floor metric
+     - Threshold
+   * - ``Δ5S`` (5-syndrome battery)
+     - ≥ 0 (no regression)
+   * - ``Δ5T`` (5-transfer battery)
+     - ≥ 0 (no regression)
+   * - ``Δ5F`` (5-falsification battery)
+     - ≥ 0 (no regression)
+   * - ε-coverage at published frontiers
+     - ≥ floor specified per-frontier
+   * - ``audit_completeness``
+     - = 1.0 (every state-change row hashes through ``audit_events``)
+   * - ``hard_regression_flag``
+     - = false (no ScoredFork hard regress)
 
 A proposer can additionally declare lab-specific ceiling metrics
 (e.g., "this upgrade is for combinatorial reasoning; please verify