feat(P3): IHF Phase 3 complete — Governance and Decision Linkage

Implements the full governance layer:
- Schema: requirements, decision_records, policy_references,
  implementation_change_references; requirement_candidates gets
  requirement_id back-reference
- RequirementsController (index/show; promotion-only create)
- DecisionRecordsController (CRUD + policy/impl ref management)
- GovernanceDashboardAction on HubsController (AutoRefresh)
- PromoteToRequirementAction + LinkToDecisionAction on candidates
- Outcome immutability enforced at controller level (fill excludes outcome)
- Full six-outcome vocabulary with Tailwind color roles
- Integration tests for all Phase 3 paths
- FrontController: registers Phase 2 missing controllers + all Phase 3
- SCOPE.md + docs/phase3-summary.md updated

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Web/View/DecisionRecords/Edit.hs

@@ -0,0 +1,34 @@
+module Web.View.DecisionRecords.Edit where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+import Web.View.DecisionRecords.New (renderForm)
+
+data EditView = EditView
+    { record       :: !DecisionRecord
+    , requirements :: ![Requirement]
+    , candidates   :: ![RequirementCandidate]
+    , users        :: ![User]
+    }
+
+instance View EditView where
+    html EditView { .. } = [hsx|
+        <div class="mb-6 flex items-center gap-2 text-sm text-gray-500">
+            <a href={DecisionRecordsAction} class="hover:text-gray-700">Decisions</a>
+            <span>/</span>
+            <a href={ShowDecisionRecordAction { decisionRecordId = record.id }}
+               class="hover:text-gray-700">{record.title}</a>
+            <span>/</span>
+            <span>Edit</span>
+        </div>
+
+        <div class="max-w-2xl">
+            <h1 class="text-2xl font-semibold mb-2">Edit Decision Record</h1>
+            <p class="text-sm text-amber-600 mb-6">
+                Note: outcome is immutable and cannot be changed here.
+            </p>
+            {renderForm record requirements candidates users (UpdateDecisionRecordAction { decisionRecordId = record.id })}
+        </div>
+    |]

Web/View/DecisionRecords/Index.hs

@@ -0,0 +1,108 @@
+module Web.View.DecisionRecords.Index where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data IndexView = IndexView
+    { records        :: ![DecisionRecord]
+    , requirements   :: ![Requirement]
+    , users          :: ![User]
+    , mOutcomeFilter :: !(Maybe Text)
+    }
+
+allOutcomes :: [Text]
+allOutcomes = ["accepted", "rejected", "deferred", "split", "merged", "reframed"]
+
+instance View IndexView where
+    html IndexView { .. } = [hsx|
+        <div class="flex items-center justify-between mb-6">
+            <h1 class="text-2xl font-semibold">Decision Records</h1>
+            <a href={NewDecisionRecordAction}
+               class="bg-indigo-600 text-white text-sm px-4 py-2 rounded hover:bg-indigo-700">
+                New Decision
+            </a>
+        </div>
+
+        <!-- Outcome filter tabs -->
+        <div class="flex gap-2 mb-5 text-sm flex-wrap">
+            <a href={DecisionRecordsAction}
+               class={filterTabClass Nothing mOutcomeFilter}>All</a>
+            {forEach allOutcomes (\o -> [hsx|
+                <a href={decisionFilterUrl o}
+                   class={filterTabClass (Just o) mOutcomeFilter}>{o}</a>
+            |])}
+        </div>
+
+        {if null records
+            then [hsx|<p class="text-sm text-gray-400">No decision records found.</p>|]
+            else renderTable records requirements users}
+    |]
+
+decisionFilterUrl :: Text -> Text
+decisionFilterUrl o = "/DecisionRecords?outcome=" <> o
+
+renderTable :: [DecisionRecord] -> [Requirement] -> [User] -> Html
+renderTable records reqs users = [hsx|
+    <div class="bg-white rounded-lg border border-gray-200 overflow-hidden">
+        <table class="w-full text-sm">
+            <thead class="bg-gray-50 border-b border-gray-200">
+                <tr>
+                    <th class="text-left px-4 py-3 font-medium text-gray-600">Title</th>
+                    <th class="text-left px-4 py-3 font-medium text-gray-600">Outcome</th>
+                    <th class="text-left px-4 py-3 font-medium text-gray-600">Requirement</th>
+                    <th class="text-left px-4 py-3 font-medium text-gray-600">Decided By</th>
+                    <th class="text-left px-4 py-3 font-medium text-gray-600">Decided At</th>
+                </tr>
+            </thead>
+            <tbody class="divide-y divide-gray-100">
+                {forEach records (renderRow reqs users)}
+            </tbody>
+        </table>
+    </div>
+|]
+
+renderRow :: [Requirement] -> [User] -> DecisionRecord -> Html
+renderRow reqs users dr = [hsx|
+    <tr class="hover:bg-gray-50">
+        <td class="px-4 py-3">
+            <a href={ShowDecisionRecordAction { decisionRecordId = dr.id }}
+               class="text-indigo-600 hover:text-indigo-800 font-medium">{dr.title}</a>
+        </td>
+        <td class="px-4 py-3">
+            <span class={outcomeClass dr.outcome <> " text-xs px-2 py-0.5 rounded font-medium"}>
+                {dr.outcome}
+            </span>
+        </td>
+        <td class="px-4 py-3 text-gray-600">
+            {linkedReqTitle reqs dr.requirementId}
+        </td>
+        <td class="px-4 py-3 text-gray-600">
+            {userName users dr.decidedBy}
+        </td>
+        <td class="px-4 py-3 text-gray-400 text-xs">{show dr.decidedAt}</td>
+    </tr>
+|]
+
+linkedReqTitle :: [Requirement] -> Maybe (Id Requirement) -> Text
+linkedReqTitle _    Nothing    = "—"
+linkedReqTitle reqs (Just rid) = maybe "(unknown)" (.title) (find (\r -> r.id == rid) reqs)
+
+userName :: [User] -> Maybe (Id User) -> Text
+userName _     Nothing    = "—"
+userName users (Just uid) = maybe "(unknown)" (.name) (find (\u -> u.id == uid) users)
+
+outcomeClass :: Text -> Text
+outcomeClass "accepted"  = "bg-green-100 text-green-800"
+outcomeClass "rejected"  = "bg-red-100 text-red-800"
+outcomeClass "deferred"  = "bg-gray-100 text-gray-600"
+outcomeClass "split"     = "bg-purple-100 text-purple-800"
+outcomeClass "merged"    = "bg-indigo-100 text-indigo-800"
+outcomeClass "reframed"  = "bg-orange-100 text-orange-800"
+outcomeClass _           = "bg-gray-100 text-gray-600"
+
+filterTabClass :: Maybe Text -> Maybe Text -> Text
+filterTabClass a b
+    | a == b    = "px-3 py-1.5 rounded bg-indigo-100 text-indigo-700 font-medium"
+    | otherwise = "px-3 py-1.5 rounded text-gray-600 hover:bg-gray-100"

Web/View/DecisionRecords/New.hs

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+module Web.View.DecisionRecords.New where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data NewView = NewView
+    { record       :: !DecisionRecord
+    , requirements :: ![Requirement]
+    , candidates   :: ![RequirementCandidate]
+    , users        :: ![User]
+    }
+
+instance View NewView where
+    html NewView { .. } = [hsx|
+        <div class="mb-6 flex items-center gap-2 text-sm text-gray-500">
+            <a href={DecisionRecordsAction} class="hover:text-gray-700">Decisions</a>
+            <span>/</span>
+            <span>New</span>
+        </div>
+
+        <div class="max-w-2xl">
+            <h1 class="text-2xl font-semibold mb-6">New Decision Record</h1>
+            {renderForm record requirements candidates users CreateDecisionRecordAction}
+        </div>
+    |]
+
+renderForm :: DecisionRecord -> [Requirement] -> [RequirementCandidate] -> [User] -> action -> Html
+renderForm record requirements candidates users submitAction = [hsx|
+    <form method="POST" action={submitAction} class="bg-white rounded-lg border border-gray-200 px-6 py-5 space-y-4">
+        {hiddenField "authenticity_token"}
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-1">Title</label>
+            <input type="text" name="title" value={record.title}
+                   class="w-full border border-gray-300 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500"
+                   required />
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-1">Outcome</label>
+            <select name="outcome"
+                    class="w-full border border-gray-300 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500">
+                <option value="accepted">accepted</option>
+                <option value="rejected">rejected</option>
+                <option value="deferred">deferred</option>
+                <option value="split">split</option>
+                <option value="merged">merged</option>
+                <option value="reframed">reframed</option>
+            </select>
+            <p class="text-xs text-gray-400 mt-1">Outcome cannot be changed after creation.</p>
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-1">Rationale</label>
+            <textarea name="rationale" rows="4"
+                      class="w-full border border-gray-300 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500"
+                      required>{record.rationale}</textarea>
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-1">Linked Requirement (optional)</label>
+            <select name="requirementId"
+                    class="w-full border border-gray-300 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500">
+                <option value="">— None —</option>
+                {forEach requirements (\r -> [hsx|<option value={show r.id}>{r.title}</option>|])}
+            </select>
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-1">Linked Candidate (optional)</label>
+            <select name="candidateId"
+                    class="w-full border border-gray-300 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500">
+                <option value="">— None —</option>
+                {forEach candidates (\c -> [hsx|<option value={show c.id}>{c.title}</option>|])}
+            </select>
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium text-gray-700 mb-1">Notes (optional)</label>
+            <textarea name="notes" rows="2"
+                      class="w-full border border-gray-300 rounded px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500"
+                      placeholder="For split/merged: list related candidate IDs or context"
+                      >{maybe "" id record.notes}</textarea>
+        </div>
+
+        <div class="flex gap-3 pt-2">
+            <button type="submit"
+                    class="bg-indigo-600 text-white text-sm px-4 py-2 rounded hover:bg-indigo-700">
+                Create Decision
+            </button>
+            <a href={DecisionRecordsAction}
+               class="text-sm text-gray-500 px-4 py-2 rounded hover:bg-gray-100">Cancel</a>
+        </div>
+    </form>
+|]

Web/View/DecisionRecords/Show.hs

@@ -0,0 +1,206 @@
+module Web.View.DecisionRecords.Show where
+
+import Web.Types
+import Generated.Types
+import IHP.Prelude
+import IHP.ViewPrelude
+
+data ShowView = ShowView
+    { record       :: !DecisionRecord
+    , policyRefs   :: ![PolicyReference]
+    , implRefs     :: ![ImplementationChangeReference]
+    , mRequirement :: !(Maybe Requirement)
+    , mCandidate   :: !(Maybe RequirementCandidate)
+    , users        :: ![User]
+    }
+
+instance View ShowView where
+    html ShowView { .. } = [hsx|
+        <div class="mb-6 flex items-center gap-2 text-sm text-gray-500">
+            <a href={DecisionRecordsAction} class="hover:text-gray-700">Decisions</a>
+            <span>/</span>
+            <span>{record.title}</span>
+        </div>
+
+        <div class="max-w-3xl space-y-6">
+            <!-- Header card -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-5">
+                <div class="flex items-start justify-between mb-3">
+                    <h1 class="text-2xl font-semibold">{record.title}</h1>
+                    <div class="flex gap-2 ml-4">
+                        <span class={outcomeClass record.outcome <> " text-xs px-2 py-0.5 rounded font-medium"}>
+                            {record.outcome}
+                        </span>
+                        <a href={EditDecisionRecordAction { decisionRecordId = record.id }}
+                           class="text-sm border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-50">
+                            Edit
+                        </a>
+                    </div>
+                </div>
+                <div class="text-xs text-gray-400 mb-3">
+                    Decided by: {userName users record.decidedBy} · {show record.decidedAt}
+                </div>
+                <div class="mb-3">
+                    <p class="text-xs font-semibold text-gray-500 uppercase tracking-wide mb-1">Rationale</p>
+                    <p class="text-sm text-gray-700 leading-relaxed">{record.rationale}</p>
+                </div>
+                {maybe mempty renderNotes record.notes}
+            </div>
+
+            <!-- Linked requirement -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <h2 class="text-sm font-semibold text-gray-700 mb-2">Linked Requirement</h2>
+                {case mRequirement of
+                    Nothing  -> [hsx|<p class="text-sm text-gray-400">No requirement linked.</p>|]
+                    Just req -> [hsx|
+                        <a href={ShowRequirementAction { requirementId = req.id }}
+                           class="text-sm text-indigo-600 hover:text-indigo-800">{req.title}</a>
+                    |]}
+            </div>
+
+            <!-- Source candidate -->
+            {maybe mempty renderCandidateSection mCandidate}
+
+            <!-- Policy references -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <h2 class="text-sm font-semibold text-gray-700 mb-3">Policy References</h2>
+                {forEach policyRefs renderPolicyRef}
+                <form method="POST" action={AddPolicyReferenceAction { decisionRecordId = record.id }}
+                      class="mt-3 flex items-end gap-2">
+                    {hiddenField "authenticity_token"}
+                    <div>
+                        <label class="text-xs text-gray-500 block mb-1">Scope</label>
+                        <select name="policyScope"
+                                class="text-sm border border-gray-300 rounded px-2 py-1.5">
+                            <option value="internal">internal</option>
+                            <option value="external">external</option>
+                            <option value="regulatory">regulatory</option>
+                            <option value="contractual">contractual</option>
+                            <option value="architectural">architectural</option>
+                        </select>
+                    </div>
+                    <div class="flex-1">
+                        <label class="text-xs text-gray-500 block mb-1">Constraint note (optional)</label>
+                        <input type="text" name="constraintNote"
+                               class="w-full text-sm border border-gray-300 rounded px-2 py-1.5"
+                               placeholder="e.g. GDPR Art. 17 right-to-erasure" />
+                    </div>
+                    <button type="submit"
+                            class="text-sm bg-gray-100 border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-200">
+                        Add
+                    </button>
+                </form>
+            </div>
+
+            <!-- Implementation references -->
+            <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+                <h2 class="text-sm font-semibold text-gray-700 mb-3">Implementation References</h2>
+                {forEach implRefs renderImplRef}
+                <form method="POST" action={AddImplementationRefAction { decisionRecordId = record.id }}
+                      class="mt-3 flex items-end gap-2">
+                    {hiddenField "authenticity_token"}
+                    <div>
+                        <label class="text-xs text-gray-500 block mb-1">System</label>
+                        <select name="system"
+                                class="text-sm border border-gray-300 rounded px-2 py-1.5">
+                            <option value="github">github</option>
+                            <option value="linear">linear</option>
+                            <option value="jira">jira</option>
+                            <option value="other">other</option>
+                        </select>
+                    </div>
+                    <div class="flex-1">
+                        <label class="text-xs text-gray-500 block mb-1">Work item ref</label>
+                        <input type="text" name="workItemRef"
+                               class="w-full text-sm border border-gray-300 rounded px-2 py-1.5"
+                               placeholder="e.g. #1234, PROJ-456" />
+                    </div>
+                    <button type="submit"
+                            class="text-sm bg-gray-100 border border-gray-300 px-3 py-1.5 rounded hover:bg-gray-200">
+                        Add
+                    </button>
+                </form>
+            </div>
+        </div>
+    |]
+
+renderNotes :: Text -> Html
+renderNotes notes = [hsx|
+    <div class="mt-2">
+        <p class="text-xs font-semibold text-gray-500 uppercase tracking-wide mb-1">Notes</p>
+        <p class="text-sm text-gray-600 italic">{notes}</p>
+    </div>
+|]
+
+renderCandidateSection :: RequirementCandidate -> Html
+renderCandidateSection c = [hsx|
+    <div class="bg-white rounded-lg border border-gray-200 px-6 py-4">
+        <h2 class="text-sm font-semibold text-gray-700 mb-2">Source Candidate</h2>
+        <a href={ShowRequirementCandidateAction { requirementCandidateId = c.id }}
+           class="text-sm text-indigo-600 hover:text-indigo-800">{c.title}</a>
+    </div>
+|]
+
+renderPolicyRef :: PolicyReference -> Html
+renderPolicyRef ref = [hsx|
+    <div class="flex items-start justify-between py-2 border-b border-gray-100 last:border-0">
+        <div class="flex items-center gap-2 text-sm">
+            <span class={policyScopeClass ref.policyScope <> " text-xs px-2 py-0.5 rounded font-medium"}>
+                {ref.policyScope}
+            </span>
+            {maybe mempty (\n -> [hsx|<span class="text-gray-600">{n}</span>|]) ref.constraintNote}
+            <span class="text-xs text-gray-400">{show ref.createdAt}</span>
+        </div>
+        <form method="POST"
+              action={DeletePolicyReferenceAction { policyReferenceId = ref.id }}>
+            {hiddenField "authenticity_token"}
+            <button type="submit"
+                    class="text-xs text-red-500 hover:text-red-700 ml-2">Remove</button>
+        </form>
+    </div>
+|]
+
+renderImplRef :: ImplementationChangeReference -> Html
+renderImplRef ref = [hsx|
+    <div class="flex items-start justify-between py-2 border-b border-gray-100 last:border-0">
+        <div class="flex items-center gap-2 text-sm">
+            <span class={systemBadgeClass ref.system <> " text-xs px-2 py-0.5 rounded font-medium"}>
+                {ref.system}
+            </span>
+            <span class="font-mono text-gray-700">{ref.workItemRef}</span>
+            <span class="text-xs text-gray-400">{show ref.linkedAt}</span>
+        </div>
+        <form method="POST"
+              action={DeleteImplementationRefAction { implementationChangeReferenceId = ref.id }}>
+            {hiddenField "authenticity_token"}
+            <button type="submit"
+                    class="text-xs text-red-500 hover:text-red-700 ml-2">Remove</button>
+        </form>
+    </div>
+|]
+
+outcomeClass :: Text -> Text
+outcomeClass "accepted"  = "bg-green-100 text-green-800"
+outcomeClass "rejected"  = "bg-red-100 text-red-800"
+outcomeClass "deferred"  = "bg-gray-100 text-gray-600"
+outcomeClass "split"     = "bg-purple-100 text-purple-800"
+outcomeClass "merged"    = "bg-indigo-100 text-indigo-800"
+outcomeClass "reframed"  = "bg-orange-100 text-orange-800"
+outcomeClass _           = "bg-gray-100 text-gray-600"
+
+policyScopeClass :: Text -> Text
+policyScopeClass "regulatory"   = "bg-red-50 text-red-700 border border-red-200"
+policyScopeClass "contractual"  = "bg-orange-50 text-orange-700 border border-orange-200"
+policyScopeClass "external"     = "bg-yellow-50 text-yellow-700 border border-yellow-200"
+policyScopeClass "architectural"= "bg-blue-50 text-blue-700 border border-blue-200"
+policyScopeClass _              = "bg-gray-50 text-gray-600 border border-gray-200"
+
+systemBadgeClass :: Text -> Text
+systemBadgeClass "github" = "bg-gray-800 text-white"
+systemBadgeClass "linear" = "bg-violet-100 text-violet-800"
+systemBadgeClass "jira"   = "bg-blue-100 text-blue-800"
+systemBadgeClass _        = "bg-gray-100 text-gray-600"
+
+userName :: [User] -> Maybe (Id User) -> Text
+userName _     Nothing    = "—"
+userName users (Just uid) = maybe "(unknown)" (.name) (find (\u -> u.id == uid) users)