Remove arc-paste / share stack — revert to legacy planner

Makefile

@@ -104,11 +104,6 @@ build-bin: ## Build arc binary with embedded web UI (requires frontend built fir
 build-quick: ## Build CLI-only binary (no embedded web UI)
 	$(BUILD_SCRIPT)
 
-.PHONY: build-paste
-build-paste: web-build ## Build arc-paste standalone binary (with embedded SPA)
-	@echo "==> Building arc-paste binary..."
-	$(GO) build -tags webui -o $(BIN_DIR)/arc-paste ./arc-paste
-
 .PHONY: release
 release: ## Build release with goreleaser (requires git tag)
 	goreleaser release --clean

api/openapi.yaml

@@ -35,8 +35,6 @@ tags:
     description: AI session and agent observability
   - name: plans
     description: Ephemeral plan review artifacts
-  - name: shares
-    description: Author-side keyring of paste shares created on this machine
 
 paths:
   # ====================
@@ -1016,83 +1014,6 @@ paths:
         "500":
           $ref: "#/components/responses/InternalError"
 
-  # ====================
-  # Shares (author keyring)
-  # ====================
-  /shares:
-    get:
-      operationId: listShares
-      tags: [shares]
-      summary: List authored shares from the local keyring
-      responses:
-        "200":
-          description: List of shares (newest first)
-          content:
-            application/json:
-              schema:
-                type: array
-                items:
-                  $ref: "#/components/schemas/Share"
-        "500":
-          $ref: "#/components/responses/InternalError"
-
-    post:
-      operationId: upsertShare
-      tags: [shares]
-      summary: Insert or replace a share keyring entry
-      requestBody:
-        required: true
-        content:
-          application/json:
-            schema:
-              $ref: "#/components/schemas/UpsertShareRequest"
-      responses:
-        "200":
-          description: Share stored
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Share"
-        "400":
-          $ref: "#/components/responses/BadRequest"
-        "500":
-          $ref: "#/components/responses/InternalError"
-
-  /shares/{shareId}:
-    parameters:
-      - name: shareId
-        in: path
-        required: true
-        description: Share ID (server-generated by the paste host)
-        schema:
-          type: string
-
-    get:
-      operationId: getShare
-      tags: [shares]
-      summary: Get a single share keyring entry
-      responses:
-        "200":
-          description: Share record
-          content:
-            application/json:
-              schema:
-                $ref: "#/components/schemas/Share"
-        "404":
-          $ref: "#/components/responses/NotFound"
-        "500":
-          $ref: "#/components/responses/InternalError"
-
-    delete:
-      operationId: deleteShare
-      tags: [shares]
-      summary: Remove a share from the keyring (idempotent)
-      responses:
-        "204":
-          description: Share removed (or absent — same response)
-        "500":
-          $ref: "#/components/responses/InternalError"
-
   # ====================
   # Issue-Label Associations (project-scoped)
   # ====================
@@ -1979,48 +1900,6 @@ components:
         label:
           type: string
 
-    # ====================
-    # Share Schemas
-    # ====================
-    Share:
-      type: object
-      required: [id, kind, url, key_b64url, edit_token, created_at]
-      properties:
-        id:
-          type: string
-        kind:
-          $ref: "#/components/schemas/ShareKind"
-        url:
-          type: string
-        key_b64url:
-          type: string
-        edit_token:
-          type: string
-        plan_file:
-          type: string
-        created_at:
-          type: string
-          format: date-time
-    ShareKind:
-      type: string
-      enum: [local, shared]
-    UpsertShareRequest:
-      type: object
-      required: [id, kind, url, key_b64url, edit_token]
-      properties:
-        id:
-          type: string
-        kind:
-          $ref: "#/components/schemas/ShareKind"
-        url:
-          type: string
-        key_b64url:
-          type: string
-        edit_token:
-          type: string
-        plan_file:
-          type: string
-
     # ====================
     # Comment Schemas
     # ====================
@@ -2259,14 +2138,12 @@ components:
     # ====================
     Config:
       type: object
-      required: [cli, server, share, updates]
+      required: [cli, server, updates]
       properties:
         cli:
           $ref: "#/components/schemas/CLIConfig"
         server:
           $ref: "#/components/schemas/ServerConfig"
-        share:
-          $ref: "#/components/schemas/ShareConfig"
         updates:
           $ref: "#/components/schemas/UpdatesConfig"
 
@@ -2287,14 +2164,6 @@ components:
         db_path:
           type: string
 
-    ShareConfig:
-      type: object
-      properties:
-        author:
-          type: string
-        server:
-          type: string
-
     UpdatesConfig:
       type: object
       properties:
@@ -2304,7 +2173,7 @@ components:
 
     ConfigResponse:
       type: object
-      required: [cli, server, share, updates, meta]
+      required: [cli, server, updates, meta]
       allOf:
         - $ref: "#/components/schemas/Config"
         - type: object