Add contact memories to inbound agent context

[alex-w-99]

Decisions

• Memory source: Use memories attached to verified inbound webhook contacts so each turn receives current context without another request.
• Default behavior: Enable memories by default, with platform configuration taking precedence over INKBOX_CONTACT_MEMORIES_ENABLED.
• Prompt safety: Keep routing metadata first and encode memories as delimited background data rather than instructions.

Changes

• Add matched-contact memory context to email, SMS, iMessage, reactions, voice transcripts, realtime calls, and call consultations.
• Preserve existing contact-card context while filtering blank or duplicate memories and injecting one block per text burst.
• Document the setting, expose it in the manifest, and bump the plugin to 0.2.7.

Verification

• uv run ruff check .
• uv run pytest -q (309 passed, 24 skipped)
• git diff --check

Related PRs

• Add contact memories to inbound agent context claude-code-plugin#50
• Add contact memories to inbound agent context codex-plugin#33
• Add contact memories to inbound agent context opencode-plugin#14
• Add contact memories to inbound agent context openclaw-plugin#50