Fix mathematical operator rendering in the tutorial and proof notes

[GoGoKo699]

GitHub rejects \operatorname in the tutorial bridge's leading-reflection formula. Replace all 35 instances in seven current exposition/proof notes with \mathop{\mathrm{NAME}}\nolimits and a delimiter space, preserving upright operator text and spacing. Record the compatible syntax in AGENTS.md.

The seven-note diff consists solely of these notation substitutions. Mathematical statements, arguments, numerical code, reference values and comparison policy are unchanged. All 27 imported scientific/history inputs and dated assessment/reader records retain their bytes. The compatible notation follows the reported workaround in github/markup #1688.

Validation: all 1,076 expressions render in local KaTeX 0.16.22 and MathJax 3.2.2; the repaired formula was rendered to SVG/PNG and visually inspected. Integrity passes for 27 inputs and 296 local links. All 60 supplementary checks and all five scientific suites (28 groups, 272 controls) pass locally, in the checked PR workflow and after merge. These local renderers check syntax and output; they do not reproduce GitHub's frontend policy.

Revision	Evidence
Candidate 8f64e18c58cf8220970e4a3f906e0ce129274edb	Full local verification and exact-substitution comparison
Checked PR merge 0c2d2ed464196bc78c428c447a0ca277527b9963	Successful run 37654486011, job 112906010981; full logs inspected
Main abdfc2cac57b5cae8bce1ef69c720e512ee0fa15	Successful run 37655452311, job 112909289821; full logs and every successful completed step inspected

All three revisions have tree 575d13c3f08e66869f6e7712a41e8fac2dd42697. Local comparisons contain one Python-version metadata difference per suite. PR and main comparisons each retain 526 raw differences, including eight suite-07 ODE-workload counters accepted by the unchanged suite07-workload-v1 policy. All assertions, counts and recorded reference-agreement checks pass; hosted outputs are not byte-identical to the references.

Retained verification-evidence artifacts:

• PR: ID 11497468980, digest sha256:b35fa3ebdaddad04446d951e9664384ac05fdfdd679c3697acf95d51464ebd1f, expires 2026-10-21T16:50:53Z.
• Main: ID 11498486817, digest sha256:d6f8a5a42c9a9ef71a5b378f57184b8873c9bc81278c4e30a06cd3687a86f639, expires 2026-10-21T16:58:19Z.

Fresh local evidence is in math-rendering-2026-10-08-evidence, including the initial delimiter-related parse failures, their correction, rendering reports, source snapshot, full scientific comparisons and inspected job logs.