docs: start frontend mvp milestone

.planning/ROADMAP.md

@@ -94,5 +94,50 @@ diagnostic interview.
 - Company-specific interview packs.
 - Human ontology review console.
 
+## Milestone 2: Frontend MVP
+
+### Phase 7: Web App Shell and Diagnostic Start
+
+**Goal:** Serve the first web app from the Go service and let a job seeker
+start diagnostic practice without API tooling.
+
+**Requirements:** WEB-01, WEB-02, WEB-03
+
+**Success Criteria:**
+
+- Go service serves a web app at `/`.
+- User can enter target role, stack, and interview timeline.
+- User can create a diagnostic session from the browser.
+- User can submit an answer and see typed grading feedback.
+- UI has loading and error states for the diagnostic flow.
+
+### Phase 8: Learning Progress View
+
+**Goal:** Show evidence-backed learning progress after practice.
+
+**Requirements:** WEB-04
+
+**Success Criteria:**
+
+- User can see learner profile and concept mastery after answering.
+- User can see readiness percentage and concept ladder state.
+- User can see the next recommended challenge and its evidence.
+- Empty states explain what to do before memory/progression exists.
+
+### Phase 9: Material and Asset Workspace
+
+**Goal:** Let an operator use ontology and teaching asset prompt workflows from
+the web app.
+
+**Requirements:** WEB-05, WEB-06, WEB-07, WEB-08
+
+**Success Criteria:**
+
+- Operator can ingest text material from the browser.
+- Operator can inspect ontology candidate concepts, edges, and gaps.
+- Operator can generate teaching asset prompt candidates from a concept.
+- UI clearly shows candidate review state, source evidence, and model
+  verification guard.
+
 ---
-*Roadmap created: 2026-04-26 after initial product planning and Go backend decision.*
+*Roadmap updated: 2026-04-26 after v2 Frontend MVP milestone start.*