feat: add scoped Slack history tool

[wamelinkwebdesign]

Summary

• Adds a scoped slack_history tool for recent messages, thread replies, and bounded channel search.
• Gates Slack recall behind SLACK_BOT_TOKEN, adds Slack/messaging toolset integration, and exposes current Slack IDs in Slack session context only when the tool is available.
• Updates Slack manifest scopes, docs, and tests for history recall behavior and safety boundaries.

Safety

• Requires explicit channel outside Slack sessions.
• Hard-caps returned messages at 100.
• Labels Slack history as untrusted data/evidence, not instructions.
• Handles missing scopes and inaccessible channels with actionable errors.

Test Plan

• TZ=UTC LANG=C.UTF-8 PYTHONHASHSEED=0 /Users/dennis/.hermes/hermes-agent/venv/bin/python -m pytest -o addopts= -n 4 --ignore=tests/integration --ignore=tests/e2e -m 'not integration' tests/tools/test_slack_history_tool.py tests/tools/test_slack_history_toolset.py tests/hermes_cli/test_slack_cli.py tests/gateway/test_slack_history_context_prompt.py -q
• Result: 16 passed in 2.08s

[alt-glitch]

Clean resubmission of closed #29473 (which was closed for bundling a Supabase memory provider plugin). This version correctly scopes to the Slack history tool only. Related to long-standing feature request #6345.

[teknium1]

Thanks for the focused resubmission. The feature addresses a current gap: gateway/session.py:496-504 still tells Slack sessions that Slack APIs cannot be called, and current main has no tracked slack_history tool.

Problems

• tools/slack_history_tool.py:111-125 passes the entire SLACK_BOT_TOKEN value as one bearer token. Hermes supports comma-separated multi-workspace tokens in website/docs/user-guide/messaging/slack.md:524-561, and the active adapter splits them in plugins/platforms/slack/adapter.py:979-992; this path would fail for those configured workspaces and cannot select the inbound workspace's credential.
• toolsets.py:62 puts the tool in _HERMES_CORE_TOOLS. All platform bundles inherit that list (toolsets.py:430-485), so any configured Slack token exposes Slack retrieval to non-Slack sessions as well. That defeats the claimed scoped boundary.

Suggested changes

• Route history calls through the active workspace-aware Slack client/token mapping and add multi-workspace coverage.
• Keep the tool Slack-scoped rather than core, and fail closed unless invocation provenance is an authorized Slack session.

Automated hermes-sweeper review.

[teknium1]

SLACK_BOT_TOKEN may be a comma-separated multi-workspace value. The active adapter splits it and maps credentials per workspace (plugins/platforms/slack/adapter.py:979-992); passing the whole value as one Bearer token fails and cannot select the workspace for this session. Please use the same workspace-aware credential path and add a multi-workspace regression test.

[teknium1]

This makes Slack history part of every hermes-* bundle because they inherit _HERMES_CORE_TOOLS. With any Slack token configured, a non-Slack session can invoke it with an explicit channel ID. Keep this in the Slack-specific bundle/toolset and enforce trusted Slack-session provenance before retrieving workspace data.

[andrexibiza]

Campaign interlock

Related: #6345. Related: #79772. Collision candidate; retain contributor credit while adjudicating #6345.