Clarify manual workspace runtime behavior

Co-Authored-By: Paperclip <noreply@paperclip.ing>

docs/docs.json

@@ -46,6 +46,7 @@
               "guides/board-operator/managing-agents",
               "guides/board-operator/org-structure",
               "guides/board-operator/managing-tasks",
+              "guides/board-operator/execution-workspaces-and-runtime-services",
               "guides/board-operator/delegation",
               "guides/board-operator/approvals",
               "guides/board-operator/costs-and-budgets",

docs/guides/board-operator/execution-workspaces-and-runtime-services.md

@@ -0,0 +1,68 @@
+---
+title: Execution Workspaces And Runtime Services
+summary: How project runtime configuration, execution workspaces, and issue runs fit together
+---
+
+This guide documents the intended runtime model for projects, execution workspaces, and issue runs in Paperclip.
+
+## Project runtime configuration
+
+You can define how to run a project on the project workspace itself.
+
+- Project workspace runtime config describes how to run services for that project checkout.
+- This is the default runtime configuration that child execution workspaces may inherit.
+- Defining the config does not start anything by itself.
+
+## Manual runtime control
+
+Runtime services are manually controlled from the UI.
+
+- Project workspace runtime services are started and stopped from the project workspace UI.
+- Execution workspace runtime services are started and stopped from the execution workspace UI.
+- Paperclip does not automatically start or stop these runtime services as part of issue execution.
+- Paperclip also does not automatically restart workspace runtime services on server boot.
+
+## Execution workspace inheritance
+
+Execution workspaces isolate code and runtime state from the project primary workspace.
+
+- An isolated execution workspace has its own checkout path, branch, and local runtime instance.
+- The runtime configuration may inherit from the linked project workspace by default.
+- The execution workspace may override that runtime configuration with its own workspace-specific settings.
+- The inherited configuration answers "how to run the service", but the running process is still specific to that execution workspace.
+
+## Issues and execution workspaces
+
+Issues are attached to execution workspace behavior, not to automatic runtime management.
+
+- An issue may create a new execution workspace when you choose an isolated workspace mode.
+- An issue may reuse an existing execution workspace when you choose reuse.
+- Multiple issues may intentionally share one execution workspace so they can work against the same branch and running runtime services.
+- Assigning or running an issue does not automatically start or stop runtime services for that workspace.
+
+## Execution workspace lifecycle
+
+Execution workspaces are durable until a human closes them.
+
+- The UI can archive an execution workspace.
+- Closing an execution workspace stops its runtime services and cleans up its workspace artifacts when allowed.
+- Shared workspaces that point at the project primary checkout are treated more conservatively during cleanup than disposable isolated workspaces.
+
+## Resolved workspace logic during heartbeat runs
+
+Heartbeat still resolves a workspace for the run, but that is about code location and session continuity, not runtime-service control.
+
+1. Heartbeat resolves a base workspace for the run.
+2. Paperclip realizes the effective execution workspace, including creating or reusing a worktree when needed.
+3. Paperclip persists execution-workspace metadata such as paths, refs, and provisioning settings.
+4. Heartbeat passes the resolved code workspace to the agent run.
+5. Workspace runtime services remain manual UI-managed controls rather than automatic heartbeat-managed services.
+
+## Current implementation guarantees
+
+With the current implementation:
+
+- Project workspace runtime config is the fallback for execution workspace UI controls.
+- Execution workspace runtime overrides are stored on the execution workspace.
+- Heartbeat runs do not auto-start workspace runtime services.
+- Server startup does not auto-restart workspace runtime services.