feat(relay): unify messenger file delivery

[zikolach]

Summary

• add local /relay send-file for safe workspace file delivery to Telegram, Discord, Slack, or all paired messengers
• implement shared file validation and final-output chunk/document fallback behavior
• complete Slack live file uploads and update setup/docs/OpenSpec artifacts

Validation

• npm run typecheck
• npm test
• openspec validate add-slack-file-upload-delivery --strict

[Copilot]

Pull request overview

This PR introduces a messenger-neutral file delivery model for PiRelay, including a new local /relay send-file command for explicitly sending safe workspace files to paired Telegram/Discord/Slack bindings, completes Slack live file uploads via Slack’s external upload flow, and unifies final-output delivery behavior across messengers (chunking vs Markdown document fallback) with updated docs/specs/tests.

Changes:

• Added local /relay send-file with workspace-relative path validation and delivery to one messenger instance or all active bindings.
• Implemented Slack external upload flow (files.getUploadURLExternal → byte upload → files.completeUploadExternal) and wired Slack runtime image commands to actual uploads.
• Introduced shared final-output delivery policy utilities (mode-aware, paragraph-aware chunking, Markdown fallback) plus expanded test coverage and documentation/spec updates.

Reviewed changes

Copilot reviewed 36 out of 36 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tests/slack-runtime.test.ts	Adds Slack live upload tests + runtime tests for image upload behaviors and updated completion/no-image expectations.
tests/runtime.test.ts	Updates Telegram runtime test to set binding progress mode for completion behavior validation.
tests/relay/setup-wizard.test.ts	Ensures generated Slack manifests include files:write.
tests/relay/final-output.test.ts	Adds unit tests for shared final-output chunking and document fallback behavior.
tests/relay/file-delivery.test.ts	Adds tests for workspace file validation/loading (path safety, symlink escape, binary/size/type rejection).
tests/relay/clipboard.test.ts	Increases clipboard helper timeouts to reduce flakiness.
tests/relay-setup.test.ts	Adds parsing/completion tests for /relay send-file.
tests/integration.test.ts	Adds integration coverage for local /relay send-file delivery (Slack target + all target/paused/unsafe-path cases).
tests/channel-adapter.test.ts	Adds tests for paragraph-aware chunk packing behavior.
README.md	Documents /relay send-file, Slack files:write scope, and updated mode-aware final-output behavior.
openspec/changes/add-slack-file-upload-delivery/tasks.md	Tracks implementation tasks for Slack uploads, local file delivery, and final-output policy.
openspec/changes/add-slack-file-upload-delivery/specs/slack-relay-adapter/spec.md	Specifies Slack outbound file delivery requirements and error-handling expectations.
openspec/changes/add-slack-file-upload-delivery/specs/relay-file-delivery/spec.md	Specifies local file delivery safety rules, target resolution, and final-output fallback policy.
openspec/changes/add-slack-file-upload-delivery/specs/relay-configuration/spec.md	Specifies Slack setup guidance requirements for file upload permissions.
openspec/changes/add-slack-file-upload-delivery/specs/relay-channel-adapters/spec.md	Defines adapter capability expectations for document/file delivery consistency.
openspec/changes/add-slack-file-upload-delivery/specs/messenger-relay-sessions/spec.md	Specifies Slack image retrieval semantics + shared final-output policy across messengers.
openspec/changes/add-slack-file-upload-delivery/proposal.md	Describes motivation and scope for unified file delivery and final-output consistency.
openspec/changes/add-slack-file-upload-delivery/design.md	Captures design decisions, safety boundaries, and trade-offs for file delivery and output policy.
openspec/changes/add-slack-file-upload-delivery/.openspec.yaml	Adds OpenSpec metadata for the change set.
extensions/relay/runtime/extension-runtime.ts	Implements /relay send-file command handling, target resolution, and per-messenger delivery dispatch.
extensions/relay/core/final-output.ts	Adds shared final-output policy helpers (mode gate, Markdown file creation, chunk/file fallback).
extensions/relay/core/file-delivery.ts	Adds workspace outbound file loading + validation (path safety, symlink escape prevention, MIME/type checks).
extensions/relay/core/channel-adapter.ts	Replaces naive text chunking with paragraph-aware chunk packing logic.
extensions/relay/config/setup.ts	Extends local command parsing/completion + updates Slack setup guidance with files:write.
extensions/relay/config/setup-wizard.ts	Updates Slack checklist and manifest snippet to include files:write.
extensions/relay/adapters/telegram/runtime.ts	Refactors Markdown file naming via shared helper + refuses remote send-file + applies mode-aware completion behavior in notifications.
extensions/relay/adapters/slack/runtime.ts	Enables Slack image commands via uploads, adds send-file refusal, and uses shared final-output fallback on completion.
extensions/relay/adapters/slack/live-client.ts	Implements Slack external upload flow and adjusts live-ops creation for outbound use without Socket Mode token.
extensions/relay/adapters/slack/adapter.ts	Threads Slack thread timestamp through file uploads and button prompts.
extensions/relay/adapters/discord/runtime.ts	Adds completion final-output fallback, refuses remote send-file, and adds outbound sendFileToBoundRoute.
docs/testing.md	Updates manual testing checklist for /relay send-file and Slack files:write setup.
docs/slack-live-integration.md	Documents required Slack files:write scope for image/file delivery.
docs/slack-app-manifests/pirelay-live-bot-b.yaml	Adds files:write to checked-in Slack app manifest.
docs/slack-app-manifests/pirelay-live-bot-a.yaml	Adds files:write to checked-in Slack app manifest.
docs/config.md	Updates Slack setup guidance to include files:write and its impact on file/fallback delivery.
docs/adapters.md	Clarifies local-only nature of generic file delivery (/relay send-file) and remote refusal behavior.

[Copilot]

Pull request overview

Copilot reviewed 36 out of 36 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 36 out of 36 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

extensions/relay/adapters/telegram/runtime.ts:1876

• In the non-InProcess (broker) path, sendSessionNotification may send route.notification.lastAssistantText verbatim when progress mode is not quiet. For large completions this can exceed Telegram’s message size limits and fail delivery, since BrokerTunnelRuntime ultimately calls sendPlainText once (no chunking / document fallback). Consider keeping broker fallback to lastSummary + “/full” hint, or implement bounded paragraph-aware chunking (and ideally the same Markdown-document fallback) for the broker send path so large outputs are still deliverable.

  const mode = progressModeFor(route.binding, config);
  const fallback = status === "completed"
    ? (shouldSendFullFinalOutput(mode) ? route.notification.lastAssistantText : route.notification.lastSummary) ?? summarizeTextDeterministically(route.notification.lastAssistantText ?? "Pi task completed.")
    : route.notification.lastFailure ?? `Pi task ${status}.`;
  const imageHint = status === "completed" && !route.notification.structuredAnswer && route.notification.latestImages?.count
    ? `\n\n🖼 ${route.notification.latestImages.count} image output/file(s) available. Use /images to download.`
    : "";
  await runtime.sendToBoundChat(route.sessionKey, `${fallback}${imageHint}`);

[Copilot]

Pull request overview

Copilot reviewed 37 out of 37 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 37 out of 37 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 37 out of 37 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 37 out of 37 changed files in this pull request and generated no new comments.