Align Cycle terminology across marketplace surfaces

[CoreyRDean]

Non-technical summary

This aligns the live user-facing clauck copy with the project’s Cycle branding. The SessionStart hook now introduces installed Cycles using that term, and the marketplace metadata/examples stop mixing older “job” language into the same outward-facing surface.

Why this matters now: the README and marketplace landing already speak in Cycles, but the plugin hook and several marketplace examples still exposed older wording. Tightening that surface reduces terminology drift for new users and for agents reading the installed marketplace.

After this change, the public-facing marketplace copy and the live hook present one consistent brand term without changing how the runtime actually works.

Technical summary

• Updated plugins/clauck/hooks/sessionstart.sh so the user-facing preamble says Registered Cycles / pre-made Cycles while keeping the manifest and semantic-hook details in their existing job-oriented technical terms.
• Updated marketplace-facing copy in marketplace/index.json to use Cycle terminology and point installation guidance at ~/.clauck/.
• Swept the remaining human-facing Cycle examples in marketplace/daily-verify.md, marketplace/event-monitor.md, marketplace/inbox-zero-assist.md, and the marketplace/module-demo/ reference files.
• Left CLI verbs, frontmatter keys, placeholders like <job-name>, and internal code identifiers unchanged.
• Validation: bash -n plugins/clauck/hooks/sessionstart.sh and /usr/bin/python3 -c "import json; json.load(open('marketplace/index.json'))".
• Breaking changes: none.

Additional notes

Trade-off: this stays intentionally on the copy/UX seam and does not attempt a broader docs rewrite or agent-skill terminology migration.

Deferred follow-up: if we want full brand-term consistency later, the larger /clauck skill text and any remaining agent-facing examples can be reviewed separately without mixing that work into this small pass.

Remaining gap: some technical surfaces still correctly use job because that is the runtime/schema term, so this PR only changes the outward-facing prose where the Cycle brand is supposed to appear.