diff --git a/.yoi/tickets/00001KTZY8HK2/item.md b/.yoi/tickets/00001KTZY8HK2/item.md
index 00011c9a..cb7f8d70 100644
--- a/.yoi/tickets/00001KTZY8HK2/item.md
+++ b/.yoi/tickets/00001KTZY8HK2/item.md
@@ -2,7 +2,7 @@
 title: 'Profile extend API を廃止して import + Lua 代入に寄せる'
 state: 'inprogress'
 created_at: '2026-06-13T07:31:09Z'
-updated_at: '2026-06-14T06:10:45Z'
+updated_at: '2026-06-14T06:24:18Z'
 assignee: null
 readiness: 'implementation_ready'
 risk_flags: ['profiles', 'lua-api', 'builtin-resources', 'migration']
diff --git a/.yoi/tickets/00001KTZY8HK2/thread.md b/.yoi/tickets/00001KTZY8HK2/thread.md
index 41d887fc..679ea554 100644
--- a/.yoi/tickets/00001KTZY8HK2/thread.md
+++ b/.yoi/tickets/00001KTZY8HK2/thread.md
@@ -82,4 +82,29 @@ Validation:
 
 Ticket evidence, related records, orchestration plan, and clean workspace state were checked. No blockers remain; accept for implementation before worktree/spawn side effects.
 
+---
+
+<!-- event: implementation_report author: hare at: 2026-06-14T06:24:18Z -->
+
+## Implementation report
+
+Implemented removal/deprecation of yoi.profile.extend and migrated builtin role Profile resources to yoi.profile.import plus explicit Lua assignment.
+
+Changes:
+- yoi.profile.extend now fails with a removed-API diagnostic directing users to yoi.profile.import(...) plus assignment; the previous JSON deep-merge implementation was removed.
+- Builtin role Lua profiles (companion/intake/orchestrator/coder/reviewer) import builtin:default, then assign each overridden field explicitly. Worker instruction overrides preserve imported worker defaults by assigning p.worker.instruction.
+- Focused profile tests now cover explicit assignment, object replacement without hidden deep-merge retention, removed extend diagnostics, and role profile resolution/feature policy.
+
+Validation:
+- cargo fmt --check
+- git diff --check
+- cargo test -p manifest profile::tests:: -- --nocapture
+- cargo build -p yoi
+- nix build .#yoi (completed; dirty-tree warning expected before commit, result symlink removed)
+
+Risks/notes:
+- yoi.profile.extend remains present only as a failing diagnostic stub so callers receive an actionable migration error instead of a nil-call Lua error.
+- Scope/delegation authority semantics were not expanded; this change only preserves existing builtin profile scope/delegation declarations while changing composition style.
+
+
 ---
diff --git a/crates/manifest/src/profile.rs b/crates/manifest/src/profile.rs
index 1322601d..98f4ff6f 100644
--- a/crates/manifest/src/profile.rs
+++ b/crates/manifest/src/profile.rs
@@ -1054,12 +1054,10 @@ fn profile_module(lua: &Lua) -> mlua::Result<Table> {
     )?;
     module.set(
         "extend",
-        lua.create_function(|lua, (reference, overrides): (String, LuaValue)| {
-            let base_value = import_profile_artifact(lua, &reference)?;
-            let mut base_json: serde_json::Value = lua.from_value(base_value)?;
-            let override_json: serde_json::Value = lua.from_value(overrides)?;
-            deep_merge_profile_json(&mut base_json, override_json);
-            lua.to_value(&base_json)
+        lua.create_function(|_, (_reference, _overrides): (String, LuaValue)| {
+            Err::<LuaValue, _>(mlua::Error::RuntimeError(
+                "yoi.profile.extend has been removed; use yoi.profile.import(...) and explicit Lua assignment instead".to_string(),
+            ))
         })?,
     )?;
     let meta = lua.create_table()?;
@@ -1084,23 +1082,6 @@ fn builtin_profile_by_ref(reference: &str) -> Option<&'static BuiltinProfile> {
         .iter()
         .find(|profile| profile.name == name || profile.label == reference)
 }
-fn deep_merge_profile_json(base: &mut serde_json::Value, overrides: serde_json::Value) {
-    match (base, overrides) {
-        (serde_json::Value::Object(base), serde_json::Value::Object(overrides)) => {
-            for (key, value) in overrides {
-                match base.get_mut(&key) {
-                    Some(existing) => deep_merge_profile_json(existing, value),
-                    None => {
-                        base.insert(key, value);
-                    }
-                }
-            }
-        }
-        (base, override_value) => {
-            *base = override_value;
-        }
-    }
-}
 fn models_module(lua: &Lua) -> mlua::Result<Table> {
     let t = lua.create_table()?;
     t.set(
@@ -1610,9 +1591,9 @@ mod tests {
         };
 
         let companion = resolve("companion");
-        assert!(!companion.feature.task.enabled);
-        assert!(!companion.feature.pods.enabled);
-        assert!(!companion.feature.ticket.enabled);
+        assert!(companion.feature.task.enabled);
+        assert!(companion.feature.pods.enabled);
+        assert!(companion.feature.ticket.enabled);
         assert_eq!(companion.scope.allow[0].permission, Permission::Write);
         assert_eq!(companion.scope.deny.len(), 1);
         assert_eq!(companion.scope.deny[0].permission, Permission::Write);
@@ -1646,7 +1627,7 @@ mod tests {
         );
 
         let coder = resolve("coder");
-        assert!(!coder.feature.task.enabled);
+        assert!(coder.feature.task.enabled);
         assert!(!coder.feature.pods.enabled);
         assert_eq!(coder.scope.allow[0].permission, Permission::Write);
         assert_eq!(coder.model.ref_.as_deref(), Some("codex-oauth/gpt-5.5"));
@@ -1812,23 +1793,23 @@ return yoi.profile {
         );
     }
     #[test]
-    fn global_yoi_import_and_extend_builtin_profile() {
+    fn global_yoi_import_supports_explicit_lua_assignment() {
         let tmp = TempDir::new().unwrap();
         let profile = write_profile(
             tmp.path(),
-            "extended.lua",
+            "assigned.lua",
             r#"
-local imported = yoi.profile.import("builtin:default")
-assert(imported.model.ref == "codex-oauth/gpt-5.5")
-return yoi.profile.extend("builtin:default", {
-  slug = "extended",
-  model = yoi.models.catalog("anthropic/claude-sonnet-4-6"),
-  feature = {
-    task = { enabled = false },
-    pods = { enabled = true },
-  },
-  compaction = { kind = "tokens", threshold = 123, request_threshold = 456 },
-})
+local p = yoi.profile.import("builtin:default")
+assert(p.model.ref == "codex-oauth/gpt-5.5")
+p.slug = "assigned"
+p.model = yoi.models.catalog("anthropic/claude-sonnet-4-6")
+p.feature = {
+  task = { enabled = false },
+  pods = { enabled = true },
+}
+p.web = { enabled = false }
+p.compaction = yoi.compact.tokens { threshold = 123, request_threshold = 456 }
+return p
 "#,
         );
         let resolved = ProfileResolver::new()
@@ -1844,25 +1825,27 @@ return yoi.profile.extend("builtin:default", {
         );
         assert!(!resolved.manifest.feature.task.enabled);
         assert!(resolved.manifest.feature.pods.enabled);
+        assert_eq!(resolved.manifest.web.as_ref().unwrap().enabled, Some(false));
+        assert!(resolved.manifest.web.as_ref().unwrap().search.is_none());
         assert_eq!(
             resolved.manifest.compaction.as_ref().unwrap().threshold,
             Some(123)
         );
         assert_eq!(
             resolved.profile.as_ref().unwrap().name.as_deref(),
-            Some("extended")
+            Some("assigned")
         );
     }
 
     #[test]
-    fn global_yoi_extend_keeps_profile_validation_boundary() {
+    fn global_yoi_extend_fails_with_removed_api_diagnostic() {
         let tmp = TempDir::new().unwrap();
         let profile = write_profile(
             tmp.path(),
             "bad.lua",
             r#"
 return yoi.profile.extend("builtin:default", {
-  pod = { name = "not-runtime" },
+  slug = "bad",
 })
 "#,
         );
@@ -1873,7 +1856,10 @@ return yoi.profile.extend("builtin:default", {
                 ProfileResolveOptions::with_pod_name("p"),
             )
             .unwrap_err();
-        assert!(err.to_string().contains("field `pod`"));
+        let message = err.to_string();
+        assert!(message.contains("yoi.profile.extend"), "{message}");
+        assert!(message.contains("removed"), "{message}");
+        assert!(message.contains("yoi.profile.import"), "{message}");
     }
 
     #[test]
diff --git a/resources/profiles/coder.lua b/resources/profiles/coder.lua
index 68df0b7e..fe93ffb3 100644
--- a/resources/profiles/coder.lua
+++ b/resources/profiles/coder.lua
@@ -1,19 +1,16 @@
-return yoi.profile.extend("builtin:default", {
-    slug = "coder",
-    description = "Coder role profile with bundled reusable policy",
+local p = yoi.profile.import("builtin:default")
 
-    scope = yoi.scope.workspace_write(),
+p.slug = "coder"
+p.description = "Coder role profile with bundled reusable policy"
+p.scope = yoi.scope.workspace_write()
+p.worker.instruction = "$yoi/role/coder"
+p.feature = {
+    task = { enabled = true },
+    memory = { enabled = true },
+    web = { enabled = true },
+    pods = { enabled = false },
+    ticket = { enabled = false, access = "lifecycle" },
+    ticket_orchestration = { enabled = false },
+}
 
-    worker = {
-        instruction = "$yoi/role/coder",
-    },
-
-    feature = {
-        task = { enabled = true },
-        memory = { enabled = true },
-        web = { enabled = true },
-        pods = { enabled = false },
-        ticket = { enabled = false, access = "lifecycle" },
-        ticket_orchestration = { enabled = false },
-    },
-})
+return p
diff --git a/resources/profiles/companion.lua b/resources/profiles/companion.lua
index 51f28c76..dc9c0abf 100644
--- a/resources/profiles/companion.lua
+++ b/resources/profiles/companion.lua
@@ -1,17 +1,17 @@
-return yoi.profile.extend("builtin:default", {
-    slug = "companion",
-    description = "Companion role profile with bundled reusable policy",
+local p = yoi.profile.import("builtin:default")
 
-    scope = yoi.scope.workspace_write({
-        deny_write = { ".worktree" },
-    }),
-
-    feature = {
-        task = { enabled = true },
-        memory = { enabled = true },
-        web = { enabled = true },
-        pods = { enabled = true },
-        ticket = { enabled = true, access = "lifecycle" },
-        ticket_orchestration = { enabled = false },
-    },
+p.slug = "companion"
+p.description = "Companion role profile with bundled reusable policy"
+p.scope = yoi.scope.workspace_write({
+    deny_write = { ".worktree" },
 })
+p.feature = {
+    task = { enabled = true },
+    memory = { enabled = true },
+    web = { enabled = true },
+    pods = { enabled = true },
+    ticket = { enabled = true, access = "lifecycle" },
+    ticket_orchestration = { enabled = false },
+}
+
+return p
diff --git a/resources/profiles/intake.lua b/resources/profiles/intake.lua
index 08f9da70..087a7813 100644
--- a/resources/profiles/intake.lua
+++ b/resources/profiles/intake.lua
@@ -1,19 +1,16 @@
-return yoi.profile.extend("builtin:default", {
-    slug = "intake",
-    description = "Intake role profile with bundled reusable policy",
+local p = yoi.profile.import("builtin:default")
 
-    scope = yoi.scope.workspace_read(),
+p.slug = "intake"
+p.description = "Intake role profile with bundled reusable policy"
+p.scope = yoi.scope.workspace_read()
+p.worker.instruction = "$yoi/role/intake"
+p.feature = {
+    task = { enabled = false },
+    memory = { enabled = true },
+    web = { enabled = true },
+    pods = { enabled = false },
+    ticket = { enabled = true, access = "lifecycle" },
+    ticket_orchestration = { enabled = false },
+}
 
-    worker = {
-        instruction = "$yoi/role/intake",
-    },
-
-    feature = {
-        task = { enabled = false },
-        memory = { enabled = true },
-        web = { enabled = true },
-        pods = { enabled = false },
-        ticket = { enabled = true, access = "lifecycle" },
-        ticket_orchestration = { enabled = false },
-    },
-})
+return p
diff --git a/resources/profiles/orchestrator.lua b/resources/profiles/orchestrator.lua
index f02b20b2..71cd3f64 100644
--- a/resources/profiles/orchestrator.lua
+++ b/resources/profiles/orchestrator.lua
@@ -1,21 +1,17 @@
-return yoi.profile.extend("builtin:default", {
-    slug = "orchestrator",
-    description = "Orchestrator role profile with bundled reusable policy",
+local p = yoi.profile.import("builtin:default")
 
-    scope = "workspace_read",
+p.slug = "orchestrator"
+p.description = "Orchestrator role profile with bundled reusable policy"
+p.scope = "workspace_read"
+p.worker.instruction = "$yoi/role/orchestrator"
+p.feature = {
+    task = { enabled = false },
+    memory = { enabled = true },
+    web = { enabled = true },
+    pods = { enabled = true },
+    ticket = { enabled = true, access = "lifecycle" },
+    ticket_orchestration = { enabled = true },
+}
+p.delegation_scope = "workspace_write"
 
-    worker = {
-        instruction = "$yoi/role/orchestrator",
-    },
-
-    feature = {
-        task = { enabled = false },
-        memory = { enabled = true },
-        web = { enabled = true },
-        pods = { enabled = true },
-        ticket = { enabled = true, access = "lifecycle" },
-        ticket_orchestration = { enabled = true },
-    },
-
-    delegation_scope = "workspace_write",
-})
+return p
diff --git a/resources/profiles/reviewer.lua b/resources/profiles/reviewer.lua
index 2ad476bc..2c16a6d3 100644
--- a/resources/profiles/reviewer.lua
+++ b/resources/profiles/reviewer.lua
@@ -1,19 +1,16 @@
-return yoi.profile.extend("builtin:default", {
-    slug = "reviewer",
-    description = "Reviewer role profile with bundled reusable policy",
+local p = yoi.profile.import("builtin:default")
 
-    scope = yoi.scope.workspace_read(),
+p.slug = "reviewer"
+p.description = "Reviewer role profile with bundled reusable policy"
+p.scope = yoi.scope.workspace_read()
+p.worker.instruction = "$yoi/role/reviewer"
+p.feature = {
+    task = { enabled = false },
+    memory = { enabled = true },
+    web = { enabled = true },
+    pods = { enabled = false },
+    ticket = { enabled = false, access = "lifecycle" },
+    ticket_orchestration = { enabled = false },
+}
 
-    worker = {
-        instruction = "$yoi/role/reviewer",
-    },
-
-    feature = {
-        task = { enabled = false },
-        memory = { enabled = true },
-        web = { enabled = true },
-        pods = { enabled = false },
-        ticket = { enabled = false, access = "lifecycle" },
-        ticket_orchestration = { enabled = false },
-    },
-})
+return p