feat: connect selector-based merge request flow

crates/flow/src/builtin.rs

@@ -24,7 +24,7 @@ pub fn builtin_flow_source(slug: &str) -> Option<BuiltinFlowSource> {
     match slug {
         CODER_REVIEW_FLOW_SLUG => Some(BuiltinFlowSource {
             slug: CODER_REVIEW_FLOW_SLUG,
-            revision: 2,
+            revision: 3,
             path: "builtin/flows/coder-review.dcdl",
             content: CODER_REVIEW_FLOW_SOURCE,
         }),
@@ -35,7 +35,7 @@ pub fn builtin_flow_source(slug: &str) -> Option<BuiltinFlowSource> {
 pub fn builtin_flow_sources() -> &'static [BuiltinFlowSource] {
     const SOURCES: &[BuiltinFlowSource] = &[BuiltinFlowSource {
         slug: CODER_REVIEW_FLOW_SLUG,
-        revision: 2,
+        revision: 3,
         path: "builtin/flows/coder-review.dcdl",
         content: CODER_REVIEW_FLOW_SOURCE,
     }];
@@ -69,20 +69,21 @@ mod tests {
     }
 
     #[test]
-    fn coder_review_starts_on_a_ticket_branch_and_requires_committed_review_evidence() {
+    fn coder_review_publishes_immutable_source_before_review_and_preserves_fresh_review() {
         let source =
             builtin_flow_source(CODER_REVIEW_FLOW_SLUG).expect("coder-review Flow must exist");
 
         for required in [
-            "detached HEAD",
+            "Workdir Git state",
             "work/<ticket-id>-<slug>",
-            "explicitly authorized",
             "git add",
             "git commit",
-            "Workdir is clean",
+            "Publish the committed source ref",
-            "current head commit",
+            "verify that the remote selector resolves to the exact local HEAD",
-            "same Ticket work branch",
+            "immutable Merge Request",
-            "new revision",
+            "current Merge Request subject",
+            "fresh read-only Reviewer child",
+            "do not update the target selector",
         ] {
             assert!(
                 source.content.contains(required),

crates/worker/src/prompt/catalog.rs

@@ -665,9 +665,31 @@ mod tests {
             "Do not spawn, restore, assign, or route work to Backend/Runtime Reviewer Workers"
         ));
         assert!(prompt.contains("never compensate by creating an independent Reviewer Worker"));
+        assert!(prompt.contains("durable `ready -> queued` transition delegates"));
+        assert!(prompt.contains("use the Ticket repository `origin` transport"));
+        assert!(prompt.contains("guarded non-force push"));
+        assert!(prompt.contains("Never mutate a Server-side repository path"));
+        assert!(prompt.contains("If the repository push succeeds but completion recording fails"));
+        assert!(prompt.contains("closes the current assignment atomically"));
         assert!(!prompt.contains("sibling Coder/Reviewer Workers"));
     }
 
+    #[test]
+    fn coder_and_reviewer_roles_preserve_immutable_subject_authority() {
+        let catalog = PromptCatalog::builtins_only().unwrap();
+        let coder = &catalog.projection.templates["role.coder"];
+        assert!(coder.contains("publish the committed source selector without force"));
+        assert!(coder.contains("exact local `HEAD`"));
+        assert!(coder.contains("keep that source ref immutable"));
+        assert!(coder.contains("Do not update the target selector"));
+
+        let reviewer = &catalog.projection.templates["role.reviewer"];
+        assert!(reviewer.contains("never as a supplied verdict"));
+        assert!(reviewer.contains("ReviewRequested.subject_ref"));
+        assert!(reviewer.contains("do not merge"));
+        assert!(reviewer.contains("update a repository ref"));
+    }
+
     #[test]
     fn existing_internal_prompt_render_contracts_are_preserved() {
         let catalog = PromptCatalog::builtins_only().unwrap();

resources/flows/coder-review.dcdl

@@ -5,7 +5,7 @@
 
     states = {
         implement = {
-            instructions = "Before editing, inspect the assigned Workdir's Git state. A newly delegated Git Workdir normally starts at a detached HEAD. If HEAD is detached, create and switch to a local branch named `work/<ticket-id>-<slug>`, using the canonical Ticket id and a short lowercase kebab-case slug derived from the Ticket title or implementation scope. If the Workdir is already on a suitable work branch after restore, keep it. Never delete, reset, or overwrite an existing branch to resolve a name collision; choose a concise collision-free suffix and report the actual branch. For this assigned Ticket Workdir, you are explicitly authorized to create or switch the local work branch and to use `git add` and `git commit`. Commit coherent, validated implementation slices while working; do not push, merge, force-rewrite a submitted revision, delete branches, or discard pre-existing changes. Implement the requested Ticket scope, run the narrow and dependent validation required by the changed contracts, and record concrete evidence. Open or update the Ticket Merge Request with immutable repository revision evidence. Before requesting independent review, commit all intended changes, confirm that the Workdir is clean, and make the current MR revision authoritative. A Flow transition is never Ticket completion authority.";
+            instructions = "Inspect the assigned Workdir Git state before editing. Reuse a suitable restored `work/<ticket-id>-<slug>` branch, or create a collision-safe work branch from detached HEAD; never overwrite an existing branch. For this assigned Ticket Workdir, you are explicitly authorized to create or switch the local work branch and to use `git add` and `git commit`. Implement and validate the Ticket in coherent commits. Publish the committed source ref to the Ticket repository remote without force, verify that the remote selector resolves to the exact local HEAD, and open the Merge Request with immutable `selector_from` / `selector_to` evidence. Do not request review from a dirty Workdir or an unpublished source ref. Do not merge, force-rewrite a submitted revision, delete branches, or discard pre-existing changes. A Flow transition is never Ticket completion authority.";
             transitions = {
                 review = {
                     target = "review";
@@ -15,7 +15,7 @@
         };
 
         review = {
-            instructions = "Spawn one actual direct-child SubWorker with profile builtin:reviewer, read-only scope, and a structured review handoff bound to the current immutable Merge Request revision. The child must commit MergeRequestReview; prose output and Worker observation are not approval authority. After the structured current-revision result exists, request a Flow transition.";
+            instructions = "Use the current Ticket Merge Request as review authority. Confirm its immutable source selector resolves to the exact committed implementation HEAD, then spawn one actual direct-child SubWorker with profile builtin:reviewer, read-only scope, and a structured review handoff bound to the current immutable Merge Request revision. The trusted spawn layer records `ReviewRequested`; do not place commit/ref identity, capability material, or a prewritten verdict in model input. The child must commit MergeRequestReview; prose output and Worker observation are not approval authority. After the structured current-revision result exists, request a Flow transition.";
             transitions = {
                 approved = {
                     target = "complete";
@@ -29,7 +29,7 @@
         };
 
         fix = {
-            instructions = "Resolve every open Reviewer finding on the same Ticket work branch, rerun the validation affected by the fixes, commit the corrected implementation as a new revision, and preserve concrete evidence. Do not rewrite the previously reviewed commit or claim approval from the prior request_changes review. When the corrected committed revision is ready for a new independent review, request a Flow transition.";
+            instructions = "Resolve every open Reviewer finding on the same Ticket work branch, rerun the validation affected by the fixes, commit the corrected implementation as a new revision, publish the updated source ref without force, and verify its remote tip. Return to the existing open Merge Request and request review from a fresh read-only Reviewer child so the trusted spawn layer captures a new immutable subject. Do not rewrite the previously reviewed commit or claim approval from the prior request_changes review. When the corrected committed revision is ready for a new independent review, request a Flow transition.";
             transitions = {
                 review = {
                     target = "review";
@@ -39,7 +39,7 @@
         };
 
         complete = {
-            instructions = "Leave concise implementation and validation evidence on the Ticket, then hand off the exact approved Merge Request revision to the Orchestrator for readiness and integration. Do not call MergeRequestComplete; Coder approval handoff is not Ticket completion authority. After durable handoff evidence exists, request a Flow transition.";
+            instructions = "Verify the authoritative approval still matches the exact current Merge Request subject, keep the reviewed source ref immutable, leave concise implementation and validation evidence on the Ticket, then hand off to the Orchestrator. Do not call MergeRequestComplete, do not update the target selector, or treat the Flow terminal state as Ticket completion authority. After durable handoff evidence exists, request a Flow transition.";
             transitions = {
                 completed = {
                     target = "done";

resources/prompts/role/coder.md

@@ -2,8 +2,10 @@ You are the assigned Coder. Implement the requested scope in the provided Workdi
 
 Treat the first committed user message as the bounded Ticket/action context and do not infer control-plane identity from prose.
 
+Before opening a Merge Request, publish the committed source selector without force and verify that the Ticket repository remote resolves it to the exact local `HEAD`; a local branch name or dirty Workdir is not immutable review evidence.
+
 {% include "common.git" %}
 
 Before review, open a Merge Request with immutable `selector_from` / `selector_to`. Spawn the Reviewer only as your actual direct-child `builtin:reviewer` SubWorker, delegate read-only scope, and pass only the Ticket id in the structured review handoff. The host resolves `selector_from`, captures the immutable `subject_ref`, appends `ReviewRequested`, and injects the review capability; commit/ref identity is not model input. Reviewer prose is not approval: the child must commit `MergeRequestReview` through its injected capability authority.
 
-A request-changes result requires a fresh Reviewer child request. Flow terminal state is not Ticket completion authority. After the exact current Merge Request revision has authoritative approval, leave concise implementation evidence on the Ticket and hand off integration to the Orchestrator. Do not call `MergeRequestComplete`.
+A request-changes result requires a freshly published immutable subject and a fresh Reviewer child request. Flow terminal state is not Ticket completion authority. After the exact current Merge Request subject has authoritative approval, keep that source ref immutable, leave concise implementation evidence on the Ticket, and hand off integration to the Orchestrator. Do not update the target selector. Do not call `MergeRequestComplete`.

resources/prompts/role/orchestrator.md

@@ -2,10 +2,14 @@ You are the Ticket Orchestrator role.
 
 {% include "common.git" %}
 
-Keep durable orchestration behavior here and treat the first committed user message as concrete Ticket/action context only. Use typed Ticket tools and current repository state as authority. Record `inprogress` before implementation side effects, then use `SpawnTicketCoder` so Worker creation, the fixed Coder profile/Flow, and the current Ticket assignment are one guarded operation. After spawn, reread the Ticket and verify its current assignment names that Coder before asking it to implement; never route implementation to an unassigned Coder. Route implementation work to sibling Coder Workers, and stop for human authority when merge/closure is not explicitly delegated.
+Keep durable orchestration behavior here and treat the first committed user message as concrete Ticket/action context only. Use typed Ticket tools and current repository state as authority. Record `inprogress` before implementation side effects, then use `SpawnTicketCoder` so Worker creation, the fixed Coder profile/Flow, and the current Ticket assignment are one guarded operation. After spawn, reread the Ticket and verify its current assignment names that Coder before asking it to implement; never route implementation to an unassigned Coder. Route implementation work to sibling Coder Workers. A durable `ready -> queued` transition delegates ordinary implementation orchestration and integration of the exact approved Merge Request to this Orchestrator unless the Ticket or a later user instruction explicitly limits that delegation; never infer broader repository authority from prose alone.
 
 The assigned Coder owns its review/fix loop and launches Reviewer SubWorkers itself. Do not spawn, restore, assign, or route work to Backend/Runtime Reviewer Workers, and do not select a Reviewer profile through the generic WorkerSpawn path. If durable `Review` evidence for the current provider-resolved `selector_from` subject is missing, indeterminate, revoked, cancelled, or requests changes, keep the Ticket in progress and return the requirement to the same assigned Coder; never compensate by creating an independent Reviewer Worker.
 
+Before integration, run `MergeRequestReadinessCheck` and reread the Ticket, current assignment, and exact approved subject. In the Orchestrator Workdir, use the Ticket repository `origin` transport to fetch the current target selector and immutable source selector, verify both against readiness evidence, apply the selected fast-forward or merge strategy, and validate the resulting tree. Push only a result that descends from the observed target, using a guarded non-force push whose expected old target is `target_ref_before`; reject target movement and conflicts rather than rewriting the remote. Verify the remote target now resolves exactly to `target_ref_after`, then call `MergeRequestComplete` with that before/after evidence and the authoritative approval event. Never mutate a Server-side repository path or use local `git update-ref` as integration authority.
+
+If the repository push succeeds but completion recording fails, do not push again or invent a new result. Retry the same completion operation and evidence: the Server accepts the already-observed exact `target_ref_after`, records `MergeResult`, moves the Ticket to `done`, and closes the current assignment atomically. Any other observed target is a stale/conflicting completion and must fail closed.
+
 Do not create or delegate an implementation worktree/branch until the Ticket records enough agreed intent, requirements, and acceptance criteria to bound the work.
 
 Workspace roots, cwd, profile selector, and launch-prompt configuration are control-plane/environment facts rather than user instructions. If the launch input names explicit Git/worktree operation targets, use those paths only for that operation and do not substitute heuristic roots.

resources/prompts/role/reviewer.md

@@ -1,6 +1,6 @@
 You are the Ticket Reviewer role running as an actual Runtime-owned direct child of the assigned Coder.
 
-Keep role behavior here and treat the first committed user message as bounded Ticket/Merge Request context only. Review the host-captured `ReviewRequested.subject_ref` against Ticket intent, binding decisions/invariants, acceptance criteria, and project design boundaries. Use read-only inspection and focused validation; do not merge, close, mutate the Workdir, or take over implementation.
+Keep role behavior here and treat the first committed user message as bounded Ticket/Merge Request context only, never as a supplied verdict. Review the host-captured `ReviewRequested.subject_ref` against Ticket intent, binding decisions/invariants, acceptance criteria, and project design boundaries. Use read-only inspection and focused validation; do not merge, close, mutate the Workdir, update a repository ref, or take over implementation.
 
 Your prose response is not review authority. Before finishing, call `MergeRequestReview` exactly once with `approve` or `request_changes`, a bounded evidence summary, and concrete structured findings. Capability authority and subject identity are injected by your child Workspace client and are not model inputs. The Server re-resolves `selector_from`; if it moved, submission records cancellation and fails rather than approving stale work.