Generate pod-declared runtime reminder manifests for cllama

[mostlydev]

Problem

cllama can inject runtime reminders only if Clawdapus gives each agent a deterministic context-mount artifact. Pod authors need a declarative way to attach short recurring reminders to agents without editing generated runtime files by hand.

Related: mostlydev/cllama#20

Proposal

Add pod syntax for runtime reminders and compile it during claw up into each agent's context mount.

Possible shape:

x-claw:
  context:
    runtime-reminders:
      - id: operating-focus
        text: "Keep the active operating contract visible in every turn."
        cadence: every_turn
        placement: before_feeds
        max_chars: 800

The generated artifact should be deterministic, short, and scoped per agent using the same include/override rules as existing context generation where practical.

Acceptance

• claw up emits a per-agent reminder manifest when pod config declares one.
• The manifest includes stable ids, rendered text, provenance, enabled state, cadence, placement, and max chars.
• Invalid or oversized reminder text fails fast with a clear validation error.
• Documentation explains how cllama consumes the manifest.

[mostlydev]

Closing as shipped.

Evidence:

• PR Add generic context block manifests #325 merged on 2026-06-27 at 69e64ed and added generic x-claw.context.blocks compilation.
• Release v0.25.0 was published on 2026-06-27.
• site/changelog.md documents context block manifests for v0.25.0 and links Closes #324.
• Current code writes per-agent context-blocks.json in internal/cllama/context.go and exposes it through claw-api in cmd/claw-api/agent_context.go.

No further issue work is needed here.