Move files tab and file pages to be accessible via contracts (#27)

* feat: remove Files from top-level navigation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* feat: update file links to use contract-scoped routes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* feat: add contract context to FileDetail component

- Add contractId, contractName, and onContractClick props to FileDetailProps
- Update breadcrumb navigation to show contract name with path separator
  when viewing file within a contract context
- Fall back to "Back to list" when no contract context is provided
- This enables the FileDetail component to be used within the
  /contracts/:contractId/files/:fileId route

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* feat: update routes to nest files under contracts

- Add react-router-dom for client-side routing
- Create ContractList component to list all contracts
- Create ContractDetail component with tabs (overview, files, tasks, repos)
- Create FileDetail component to view individual files
- Configure routes:
  - /contracts - list all contracts
  - /contracts/:id - view contract details with Files tab
  - /contracts/:contractId/files/:fileId - view file in contract context
- Remove standalone file routes (/files, /files/:id)

Files are now only accessible through their parent contract.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Task completion checkpoint

* Task completion checkpoint

* Task completion checkpoint

* Task completion checkpoint

* Task completion checkpoint

* Task completion checkpoint

* Task completion checkpoint

* Task completion checkpoint

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/makima/frontend/src/routes/contracts.tsx b/makima/frontend/src/routes/contracts.tsx
index 6acda29..6946cb8 100644
--- a/makima/frontend/src/routes/contracts.tsx
+++ b/makima/frontend/src/routes/contracts.tsx
@@ -375,9 +375,11 @@ function ContractsPageContent() {
   // File/task navigation handlers
   const handleFileSelect = useCallback(
     (fileId: string) => {
-      navigate(`/files/${fileId}`);
+      if (contractDetail) {
+        navigate(`/contracts/${contractDetail.id}/files/${fileId}`);
+      }
     },
-    [navigate]
+    [navigate, contractDetail]
   );
 
   const handleTaskSelect = useCallback(