feat: Sprint 23 -- profile/workspace/model coherence

Fix five coherence bugs in profile switching:
1. Model picker ignored profile default (localStorage stale key)
2. Workspace list was global (not profile-scoped)
3. DEFAULT_WORKSPACE was a boot-time singleton
4. Session list showed all profiles (no filtering)
5. switchToProfile() didn't refresh workspaces or sessions

Backend: workspace storage is now profile-local for named profiles,
switch_profile() returns default_model and default_workspace.
Frontend: switchToProfile() clears stale model pref, refreshes
workspace list and session list, sessions.js filters by active profile
with 'Show N from other profiles' toggle.

8 new tests. 400 pass / 23 fail (identical to baseline).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/workspace.py

@@ -1,43 +1,123 @@
 """
 Hermes Web UI -- Workspace and file system helpers.
+
+Workspace lists and last-used workspace are stored per-profile so each
+profile has its own workspace configuration.  State files live at
+``{profile_home}/webui_state/workspaces.json`` and
+``{profile_home}/webui_state/last_workspace.txt``.  The global STATE_DIR
+paths are used as fallback when no profile module is available.
 """
 import json
 import os
 from pathlib import Path
 
 from api.config import (
-    WORKSPACES_FILE, LAST_WORKSPACE_FILE, DEFAULT_WORKSPACE,
+    WORKSPACES_FILE as _GLOBAL_WS_FILE,
+    LAST_WORKSPACE_FILE as _GLOBAL_LW_FILE,
+    DEFAULT_WORKSPACE as _BOOT_DEFAULT_WORKSPACE,
     MAX_FILE_BYTES, IMAGE_EXTS, MD_EXTS
 )
 
 
+# ── Profile-aware path resolution ───────────────────────────────────────────
+
+def _profile_state_dir() -> Path:
+    """Return the webui_state directory for the active profile.
+
+    For the default profile, returns the global STATE_DIR (respects
+    HERMES_WEBUI_STATE_DIR env var for test isolation).
+    For named profiles, returns {profile_home}/webui_state/.
+    """
+    try:
+        from api.profiles import get_active_profile_name, get_active_hermes_home
+        name = get_active_profile_name()
+        if name and name != 'default':
+            d = get_active_hermes_home() / 'webui_state'
+            d.mkdir(parents=True, exist_ok=True)
+            return d
+    except ImportError:
+        pass
+    return _GLOBAL_WS_FILE.parent
+
+
+def _workspaces_file() -> Path:
+    """Return the workspaces.json path for the active profile."""
+    return _profile_state_dir() / 'workspaces.json'
+
+
+def _last_workspace_file() -> Path:
+    """Return the last_workspace.txt path for the active profile."""
+    return _profile_state_dir() / 'last_workspace.txt'
+
+
+def _profile_default_workspace() -> str:
+    """Read the profile's default workspace from its config.yaml.
+
+    Falls back to the boot-time DEFAULT_WORKSPACE constant.
+    """
+    try:
+        from api.profiles import get_active_hermes_home
+        from api.config import get_config
+        cfg = get_config()
+        ws = cfg.get('default_workspace')
+        if ws:
+            p = Path(ws).expanduser().resolve()
+            if p.is_dir():
+                return str(p)
+    except (ImportError, Exception):
+        pass
+    return str(_BOOT_DEFAULT_WORKSPACE)
+
+
+# ── Public API ──────────────────────────────────────────────────────────────
+
 def load_workspaces() -> list:
-    if WORKSPACES_FILE.exists():
+    ws_file = _workspaces_file()
+    if ws_file.exists():
         try:
-            return json.loads(WORKSPACES_FILE.read_text(encoding='utf-8'))
+            return json.loads(ws_file.read_text(encoding='utf-8'))
         except Exception:
             pass
-    return [{'path': str(DEFAULT_WORKSPACE), 'name': 'default'}]
+    # Fallback: try global file (migrates from pre-profile storage)
+    if _GLOBAL_WS_FILE.exists():
+        try:
+            return json.loads(_GLOBAL_WS_FILE.read_text(encoding='utf-8'))
+        except Exception:
+            pass
+    return [{'path': _profile_default_workspace(), 'name': 'default'}]
 
 
 def save_workspaces(workspaces: list):
-    WORKSPACES_FILE.write_text(json.dumps(workspaces, ensure_ascii=False, indent=2), encoding='utf-8')
+    ws_file = _workspaces_file()
+    ws_file.parent.mkdir(parents=True, exist_ok=True)
+    ws_file.write_text(json.dumps(workspaces, ensure_ascii=False, indent=2), encoding='utf-8')
 
 
 def get_last_workspace() -> str:
-    if LAST_WORKSPACE_FILE.exists():
+    lw_file = _last_workspace_file()
+    if lw_file.exists():
         try:
-            p = LAST_WORKSPACE_FILE.read_text(encoding='utf-8').strip()
+            p = lw_file.read_text(encoding='utf-8').strip()
             if p and Path(p).is_dir():
                 return p
         except Exception:
             pass
-    return str(DEFAULT_WORKSPACE)
+    # Fallback: try global file
+    if _GLOBAL_LW_FILE.exists():
+        try:
+            p = _GLOBAL_LW_FILE.read_text(encoding='utf-8').strip()
+            if p and Path(p).is_dir():
+                return p
+        except Exception:
+            pass
+    return _profile_default_workspace()
 
 
 def set_last_workspace(path: str):
     try:
-        LAST_WORKSPACE_FILE.write_text(str(path), encoding='utf-8')
+        lw_file = _last_workspace_file()
+        lw_file.parent.mkdir(parents=True, exist_ok=True)
+        lw_file.write_text(str(path), encoding='utf-8')
     except Exception:
         pass