fix(slack): declare im:read — conversations.info needs it for a DM

[zfy0701]

conversations.info takes one of channels:read / groups:read / im:read / mpim:read depending on the conversation type. The manifest declared three of the four and omitted the DM arm.

Not cosmetic. sendMessage into a DM asks getChannelInfo whether the target is one, and that lookup is deliberately written to fall back rather than fail a send that already happened — so a refused call reads as not a DM. The outbound session is then keyed as a channel thread while the inbound messages key it as a DM, and the conversation forks. getCurrentChannel in a DM also loses its name and isIm.

Found by diffing our scope list against two comparable Slack apps. Three signals agreed: Slack's own scope table for the method, our test workspace app which someone had already added im:read to by hand, and both of those apps carrying it.

This is the scope-arrives-with-its-feature rule from #1655 holding rather than bending — the consumer shipped long ago and only the grant was missed.

Verification: typecheck, lint, format:check clean; CP manifest unit 18, web console platform 21, both drift guards updated.

🤖 Generated with Claude Code

[agentconnect-md-test]

Approved — no blocking findings.

im:read is the missing DM-specific permission for conversations.info; Slack’s official method reference lists it for direct-message access, while the existing im:history and im:write grants cover different operations. The daemon depends on this lookup when classifying an outbound Slack destination for its canonical thread key and when projecting current-channel metadata.

Adding the scope to the canonical SLACK_BOT_SCOPES list reaches the manual manifest, Control Plane app creation and managed-manifest refresh, platform OAuth authorization, and grant fencing. The Control Plane and web drift guards were updated consistently, and the change does not introduce a second scope source.

Verification: the checkout was a clean synthetic merge with parents exactly matching the trusted base and head; I inspected the complete diff and traced every scope consumer, and git diff --check passed. I could not rerun the focused Vitest suites because this isolated runner lacked repository-local test binaries and Corepack’s pinned pnpm download was blocked by restricted DNS/network policy; that environment-only gap does not change the verdict for this narrow manifest correction.

_{sent by review-bot (Codex · gpt-5.6-sol) · open in session}