vfs: symlink support in file picker, test cleanup, boot mount fix

- File picker (app.filepicker.pas): add otSYMLINK to directory case in
  fp_collect_cb so symlinks like /sys appear as navigable directories
- VFS: add RemoveVirtualTree() to recursively free vdir/symlink trees
- VFS UnitTest: clean up /utest_vfs tree after all tests
- STORTEST: clean up /st_test tree after tests, fix listing leak in
  cmd_stortest (GetDirectoryListingFrom result was never freed)
- Boot mount: auto-mount boot drive at /boot via mountVolume() instead
  of symlink; remove /boot and /cfg from init() vdirs
- mount.asr: remove boot line (now only 'mnt {device}/sys /sys')

iso/mount.asr

@@ -1,2 +1 @@
-mnt {device}/boot /boot
 mnt {device}/sys /sys

src/app/app.filepicker.pas

@@ -389,7 +389,7 @@ begin
     obj := PVFSObject(data);
     if (ctx = nil) or (obj = nil) then exit;
     case obj^.ObjectType of
-        otVDIRECTORY, otDRIVE, otDIRECTORY, otMOUNT:
+        otVDIRECTORY, otDRIVE, otDIRECTORY, otMOUNT, otSYMLINK:
             if ctx^.dir_count < ENTRY_MAX then begin
                 ctx^.dir_names^[ctx^.dir_count] := key;
                 ctx^.dir_count := ctx^.dir_count + 1;

src/driver/storage/driver.storage.test.pas

@@ -129,9 +129,6 @@ begin
     res := driver.storage.vfs.ResolvePathFrom('mnt', '/');
     Assert(res = pvDirectory, 'ResolvePathFrom: /mnt from /');
 
-    res := driver.storage.vfs.ResolvePathFrom('cfg', '/');
-    Assert(res = pvDirectory, 'ResolvePathFrom: /cfg from /');
-
     { Non-existent names resolve to pvInvalid }
     res := driver.storage.vfs.ResolvePathFrom('zzznope', '/');
     Assert(res = pvInvalid, 'ResolvePathFrom: nonexistent from /');
@@ -155,7 +152,7 @@ begin
     Assert(map <> nil, 'GetDirectoryListingFrom(/) not nil');
     driver.storage.vfs.FreeDirectoryListing(map);
 
-    { /disk, /dev, /mnt, /cfg created at init — must appear in root listing }
+    { /disk, /dev, /mnt created at init — must appear in root listing }
     map := driver.storage.vfs.GetDirectoryListingFrom('/', '/');
     Assert(map <> nil, 'GetDirectoryListingFrom(/) not nil (2)');
     { All maps are now caller-owned snapshots — always safe to free }
@@ -166,10 +163,6 @@ begin
     Assert(map <> nil, 'GetDirectoryListingFrom(/dev) not nil');
     driver.storage.vfs.FreeDirectoryListing(map);
 
-    map := driver.storage.vfs.GetDirectoryListingFrom('/cfg', '/');
-    Assert(map <> nil, 'GetDirectoryListingFrom(/cfg) not nil');
-    driver.storage.vfs.FreeDirectoryListing(map);
-
     { Non-existent path returns nil (no crash) }
     map := driver.storage.vfs.GetDirectoryListingFrom('/zzznope', '/');
     Assert(map = nil, 'GetDirectoryListingFrom(nonexistent) = nil');
@@ -213,6 +206,50 @@ begin
     Assert(driver.storage.vfs.PathValid('/st_test/./') = pvDirectory,
            'PathValid with . stays put');
 
+    { ---- Symlink traversal through resolvePathFrom / ChangeDirectoryFrom ---- }
+    { Create /st_test/inner, then symlink /st_test/slink -> /st_test/inner }
+    errCode := driver.storage.vfs.newVirtualDirectory('/st_test/inner');
+    Assert(errCode = eNone, 'newVDir /st_test/inner = eNone');
+
+    errCode := driver.storage.vfs.newVirtualDirectory('/st_test/inner/deep');
+    Assert(errCode = eNone, 'newVDir /st_test/inner/deep = eNone');
+
+    errCode := driver.storage.vfs.CreateSymlink('/st_test/slink', '/st_test/inner');
+    Assert(errCode = eNone, 'CreateSymlink slink -> inner = eNone');
+
+    { resolvePathFrom through symlink }
+    res := driver.storage.vfs.ResolvePathFrom('slink', '/st_test');
+    Assert(res = pvDirectory, 'ResolvePathFrom: slink from /st_test = dir');
+
+    { resolvePathFrom through symlink + subdir }
+    res := driver.storage.vfs.ResolvePathFrom('/st_test/slink/deep', '/');
+    Assert(res = pvDirectory, 'ResolvePathFrom: slink/deep = dir');
+
+    { ChangeDirectoryFrom through symlink }
+    newDir := nil;
+    res := driver.storage.vfs.ChangeDirectoryFrom('slink', '/st_test', newDir);
+    Assert(res = pvDirectory, 'ChangeDirFrom slink: returns dir');
+    if newDir <> nil then kfree(void(newDir));
+
+    { GetDirectoryListingFrom through symlink }
+    map := driver.storage.vfs.GetDirectoryListingFrom('/st_test/slink', '/');
+    Assert(map <> nil, 'GetDirListingFrom through slink not nil');
+    if map <> nil then
+        driver.storage.vfs.FreeDirectoryListing(map);
+
+    { GetDirectoryListingFrom deeper through symlink }
+    map := driver.storage.vfs.GetDirectoryListingFrom('/st_test/slink/deep', '/');
+    Assert(map <> nil, 'GetDirListingFrom slink/deep not nil');
+    if map <> nil then
+        driver.storage.vfs.FreeDirectoryListing(map);
+
+    { Nonexistent child after symlink }
+    res := driver.storage.vfs.ResolvePathFrom('/st_test/slink/nope', '/');
+    Assert(res = pvInvalid, 'ResolvePathFrom slink/nope = invalid');
+
+    { --- Cleanup: remove all test objects from VFS tree --- }
+    driver.storage.vfs.RemoveVirtualTree('/st_test');
+
     debug.tracer.pop_trace;
 end;
 
@@ -379,6 +416,7 @@ procedure cmd_stortest(params: PParamList; stdin_buf, stdout_buf, stderr_buf: PO
 var
     passed, failed : uint32;
     pStr, fStr, msg, tmp : pchar;
+    map : PHashMap;
 begin
     passed := 0;
     failed := 0;
@@ -387,9 +425,11 @@ begin
     run_tests(passed, failed, false, stdout_buf);
 
     { Runtime-only: test /disk listing (populated only after auto_mount_volumes) }
-    if driver.storage.vfs.GetDirectoryListingFrom('/disk', '/') <> nil then
-        io.stdio.bufWriteStrLn(stdout_buf, '[+] /disk listing available (volumes mounted)')
-    else
+    map := driver.storage.vfs.GetDirectoryListingFrom('/disk', '/');
+    if map <> nil then begin
+        io.stdio.bufWriteStrLn(stdout_buf, '[+] /disk listing available (volumes mounted)');
+        driver.storage.vfs.FreeDirectoryListing(map);
+    end else
         io.stdio.bufWriteStrLn(stdout_buf, '[-] /disk listing nil (no volumes mounted)');
 
     pStr := intToString(passed);