read user-scope Claude config files via a read allow-list (D-80)

The reader opened repo-local .claude markdown but rejected user-scope
files under ~/.claude with "path outside workspace" — that dir is
global, outside the repo, and files.read was repo-confined (T-102).

Per D-76 the Claude config surface is clide-managed, so files.read now
resolves a path under an allow-list: the workspace root plus trusted
extra read roots (FilesService.extraReadRoots), wired in main.dart to
~/.claude when present. Reads widen; writes stay repo-confined, and the
symlink re-check still refuses a config-root symlink that escapes. Off-
root paths and `..` traversal are rejected as before.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

governance/README.md

@@ -121,6 +121,7 @@ You might also want, project-permitting:
 - [D-77: Drive Claude via the stream-json control protocol; teams become a clide-owned coordination layer](decisions/architecture.md#d-77-drive-claude-via-the-stream-json-control-protocol-teams-become-a-clide-owned-coordination-layer) — _architecture_
 - [D-78: Claude permission/prompt transport is the stdio control channel](decisions/architecture.md#d-78-claude-permissionprompt-transport-is-the-stdio-control-channel) — _architecture_
 - [D-79: Workspace content search is a pure-Dart in-process engine, outside pql](decisions/architecture.md#d-79-workspace-content-search-is-a-pure-dart-in-process-engine-outside-pql) — _architecture_
+- [D-80: `files.read` allows trusted Claude config roots beyond the workspace](decisions/architecture.md#d-80-filesread-allows-trusted-claude-config-roots-beyond-the-workspace) — _architecture_
 
 ## Open questions