docs: add Licensing & Usage page and reorder agents manifest - #28263

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• docs/ai-coder/agents/licensing-usage.md

Documentation Check

This is a docs-only PR, and the new page is well structured and correctly wired into docs/manifest.json. The exhaustion-behavior conflict has been resolved by trimming that section; two consistency items remain.

Updates Needed

• docs/ai-coder/agents/licensing-usage.md - Terminology mismatch. This page uses "Agent Time" throughout, but the rest of the Coder Agents docs use "Agent Hours" (getting-started.md lines 228-230, platform-controls/index.md lines 126-129). Pick one canonical term and align all pages so the docs don't describe the same billing unit under two names.
• docs/ai-coder/agents/licensing-usage.md - Exhaustion behavior conflicts with existing docs. This page says an AI Premium deployment that exhausts its allocation "may be provisioned to fall back to the Community concurrency model" (five concurrent, extras queued), which conflicts with the hard-limit behavior in platform-controls/index.md and getting-started.md. Resolved in ded1120: the two directly conflicting sentences were removed from the "AI Premium Agent Time exhaustion" section.

  ⚠️ The remaining sentence still refers to "the concurrency fallback" without describing the "Agent Hours hard limit" mechanism that the other pages use. Consider linking to Concurrent agents for the full behavior.

New Documentation Needed

• docs/reference/glossary.md - The usage-billing concept ("Agent Time" / "Agent Hours") is a user-facing Coder Agents feature name but has no glossary entry. Add one once the canonical term is settled.

Automated review via Coder Agents