mig: add MCP approval workflow tables

[daviddanialy]

Schema foundation for the MCP approval workflow (AIS-466): a request-and-approve
flow for unverified MCP servers, where an admin decides with assembled evidence
rather than the platform issuing a verdict.

Migration only — no application code. The services that read these tables follow
in later PRs.

Tables

Table	Purpose
mcp_approval_requests	One review per server per project
mcp_approval_request_requesters	Who asked and why
mcp_research_reports	Async research-agent output
mcp_approval_decisions	Append-only approve/deny history

Why these are separate from risk_policy_bypass_requests

The existing bypass request means "let me past this block": personal, one-off,
keyed per requester, satisfied by granting risk_policy:bypass. An approval
request asks whether a server is allowed at the organization at all — durable,
carrying an evidence trail and a re-review lifecycle.

The two are linked rather than merged: a block still mints a bypass request, and
mcp_approval_requests.risk_policy_bypass_request_id records a promotion.
Bending one record into the other would have compromised both.

Design notes

Evidence is JSONB in two places, deliberately. mcp_approval_requests.current_evidence
is a refreshable cache of the latest signal gather. mcp_approval_decisions.evidence_snapshot
is a frozen copy taken at decision time. The duplication is the point: a decision
record has to show what the reviewer actually saw, so it must not follow a later
refresh. JSONB rather than columns because the payload is only ever read back
whole for one request, and the signal set grows as sources are added.

Decisions are append-only. A re-review adds a row rather than replacing one,
so the sequence of decisions on a server becomes the history that a chat channel
does not preserve. granted_principal_urns records the resolved blast radius —
requester, team, or organization — rather than a mode, keeping the audit trail
honest about who was actually given access.

Approvals are project-scoped, matching risk_policies and the shadow-MCP
enforcement path so a decision can reconcile into existing grants.

No enum CHECK constraints on status / decision; allowed values are
validated in application code per the schema conventions. The CHECKs present
are structural (jsonb_typeof(...) = 'object'), matching
risk_policy_bypass_requests.target_dimensions.

Migration safety

All four tables are new, so no ACCESS EXCLUSIVE scan on an existing table and
no PG305/PG306 lint warnings. Applied locally and atlas migrate diff reports
the directory synced with schema.sql.

---

Summary by cubic

Add MCP approval workflow schema (AIS-466). Introduces project-scoped approval requests, requesters, research reports, and append-only decisions with frozen evidence to support admin review of unverified MCP servers.

• Migration
  • Adds mcp_approval_requests, mcp_approval_request_requesters, mcp_research_reports, and mcp_approval_decisions.
  • Adds dedupe/lookup indexes (incl. project + target_kind + target_key), composite FKs (request_id, project_id) so child rows can’t cross projects, unique (report_id, request_id) so decisions only cite research for the same request, unique (request_id, user_id) to dedupe requesters, and non-partial indexes to back ON DELETE cascades.
  • Evidence is JSONB with versioning; decisions snapshot evidence and are append-only; evidence_version on decisions has no default; ships a new migration and regenerated server/internal/database/models.go.

^{Written for commit 921bed8. Summary will update on new commits.}

[linear-code]

AIS-466

[changeset-bot]

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Latest commit: da1f26d

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[cubic-dev-ai]

cubic analysis

All reported issues were addressed across 4 files

Linked issue analysis

Linked issue: AIS-466: mig: MCP approval workflow schema

Status	Acceptance criteria	Notes
✅	PR is a migration (mig:) PR with the new MCP approval workflow schema committed	PR title uses the mig: prefix and the repo contains a new migration file and schema updates as part of this commit.
✅	Create mcp_approval_requests table with expected fields (target_kind, target_raw, target_key, current_evidence, evidence_version, artifact_ref, version_pinned, risk_policy_bypass_request_id, status, timestamps, soft-delete)	schema.sql contains CREATE TABLE IF NOT EXISTS mcp_approval_requests with the listed columns, constraints, and comments.
✅	Create mcp_approval_request_requesters table (requester rows attached to a request)	schema.sql and the migration file include mcp_approval_request_requesters with foreign key to mcp_approval_requests and required columns.
✅	Create mcp_research_reports table for agent findings (report JSONB, run metadata, timestamps)	schema.sql and migration add mcp_research_reports with report JSONB, versioning, model/prompt fields, timestamps, and FK to mcp_approval_requests.
✅	Create mcp_approval_decisions table (append-only decisions with evidence_snapshot, rationale, granted_principal_urns, decided_at)	schema.sql and migration add mcp_approval_decisions with evidence_snapshot JSONB, rationale, granted_principal_urns, decided_at, and FK relations.
✅	Regenerated committed DB models (models.go) matching the new schema	server/internal/database/models.go includes new generated types for McpApprovalRequest, McpApprovalRequestRequester, McpResearchReport, and McpApprovalDecision consistent with the schema additions.

<sub>Tip: instead of fixing issues one by one fix them all with cubic

Re-trigger cubic</sub>

[github-actions]

atlas migrate lint on server/migrations

Status	Step	Result
	1 new migration file detected	20260806225751_mcp-approval-workflow.sql
	ERD and visual diff generated	View Visualization
	No issues found	View Report
Read the full linting report on Atlas Cloud

[github-actions]

atlas migrate lint on server/clickhouse/migrations

Status	Step	Result
	No migration files detected
	ERD and visual diff generated	View Visualization
	No issues found	View Report
Read the full linting report on Atlas Cloud

[daviddanialy]

@cubic-dev-ai review this PR