ui: reinforce primary Participate commit flow and role CTA clarity

[MontrealAI]

Motivation

• Fix the blocking defect where the Participate > Applicant flagship lacked a visible, primary on-chain commit path so users could only prepare local packets; the UI must expose and execute the real commitApplication(...) write above the fold.

Description

• Single file change: ui/agijobmanager_genesis_job_mainnet_2026-04-03.html to restore and strengthen the primary Applicant commit surface.
• Added and ensured the primary CTA Commit application on-chain with stable id applicantCommitApplicationButton in the main Participate > Applicant panel and a mobile sticky mirror applicantCommitApplicationButtonSticky, both visible even when disabled.
• Wired the review-first flow to the real on-chain write by implementing submitApplicantCommit() and calling agiJobDiscovery.methods.commitApplication(pid, commitment, subdomain, proof).send({from:userAccount}) from the confirm step (openApplicantCommitReview → submitApplicantCommit).
• Implemented explicit blockers rendering and disabled-state management via buildApplicantCommitBlockers(state) and the applicantCommitBlockers element so the button stays visible and explains why it’s not ready.
• Kept local packet/archive features but demoted the archive into a collapsed, clearly labeled local-only <details> block (advancedLocalPacketArchive) and preserved local save/export behavior and packet persistence after on-chain success.
• Improved role copy and CTAs for clarity (Finalist / Validator / Claimant labels) and made the mobile sticky CTA show only when the Applicant rail is active.
• Commitment generation uses packed solidity hashing semantics (web3.utils.soliditySha3({type:'uint256',...},{type:'address',...},{type:'string',...},{type:'bytes32',...})) and the commit flow preserves the review-first pattern and on-success packet persistence.

Testing

• Ran npm run check:no-binaries and it passed with no forbidden binary additions.
• Ran npm run docs:check and documentation checks passed.
• Ran npm run test:ui (UI smoke test) which completed and passed (UI smoke spec connected and the test passed).

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Codex Task