Stacked on PR-1 (#2729). Computes the readable/writable namespace lists
for a workspace from the live workspaces tree at request time. No
precomputed columns, no migrations — re-parenting on canvas takes
effect immediately on the next memory call.
What ships:
- workspace-server/internal/memory/namespace/resolver.go
- walkChain: recursive CTE, walks parent_id chain to root, capped
at depth 50 to defend against malformed/cyclic data
- derive: maps a chain to (workspace, team, org) namespace strings
- ReadableNamespaces / WritableNamespaces: the public API
- CanWrite + IntersectReadable: server-side ACL helpers MCP
handlers (PR-5) will call before talking to the plugin
- resolver_test.go: 100% statement coverage
Design choices worth flagging:
- Today's tree is depth-1 (root + children). The recursive CTE
handles arbitrary depth so we don't have to revisit the resolver
when the tree deepens.
- GLOBAL→org write restriction (memories.go:167-174) is preserved
by gating the org namespace's Writable flag on parent_id IS NULL.
- Removed-status workspaces are NOT filtered from the chain walk —
matches today's TEAM behavior (memories.go:367-372 filters on
read, not on tree walk).
- IntersectReadable with empty `requested` returns ALL readable
namespaces (default-search-everything semantic from the discovery
tools spec).
This package has zero callers in this PR; integration starts in PR-5.
01b653d6b0