Name the book on the speakers page and add a project switcher

Reported: the speakers page showed 51 needing review in Chrome on Windows
and 20 in Safari on the Mac, and showed no names starting with D including
"Deal Hunter" - despite several reloads.

Neither browser was wrong. The active project is a per-browser cookie, so
each browser was on a different book and the two lists are unrelated:

  Last Dwarf                 91 speakers, 51 need checking, 0 D-names
  DealHunterShip_4.0e        61 speakers, 19 need checking, includes
                             Deal Hunter, Dealer, Distorted Voice,
                             Duchess Victoria, Duty Nurse

"Deal Hunter" is the ship AI in the Deal Hunter book and is not a Last
Dwarf character, so its absence there was correct. The page gave no hint
that the book was even part of what was being displayed.

- The speakers page now shows a "Reviewing <project>" banner next to the
  counts, so the number and the book it belongs to are read together.
- Added a project switcher directly on that page; previously changing
  project meant navigating via the dashboard.
- activate_project accepts ?next=, restricted to same-site relative paths
  so the switcher can stay put. Verified //evil.com and https://evil.com
  both fall back to "/".
- list_projects registered as a template global, following the existing
  active_project pattern; it degrades to [] on any error.

routes.py stays at its 76 pre-existing ruff errors. Suite: 684 passed, 8
pre-existing.

umbraaudio/web/routes.py

@@ -13,7 +13,7 @@ from typing import Any
 
 logger = logging.getLogger(__name__)
 
-from fastapi import APIRouter, Form, Request
+from fastapi import APIRouter, Form, Query, Request
 from fastapi.responses import FileResponse, HTMLResponse, JSONResponse
 from fastapi.templating import Jinja2Templates
 
@@ -54,6 +54,25 @@ def _active_project_for_template(request: Request) -> dict:
 templates.env.globals["active_project"] = _active_project_for_template
 
 
+def _list_projects_for_template() -> list[dict]:
+    """Every project, so the speakers page can offer a switcher.
+
+    The active project is a per-browser cookie; without a visible switcher a
+    reviewer comparing two browsers had no way to tell they were looking at
+    two different books.
+    """
+
+    from umbraaudio.config import list_projects
+
+    try:
+        return list_projects()
+    except Exception:
+        return []
+
+
+templates.env.globals["list_projects"] = _list_projects_for_template
+
+
 def _voice_maintenance_for_template() -> dict | None:
     """Expose the active voice-maintenance marker (or None) to templates."""
 
@@ -553,7 +572,11 @@ async def project_new_form(request: Request):
 
 
 @router.post("/api/projects/activate/{slug}")
-async def activate_project(request: Request, slug: str):
+async def activate_project(
+    request: Request,
+    slug: str,
+    next_url: str = Query("/", alias="next"),
+):
     from fastapi.responses import RedirectResponse
 
     from umbraaudio.config import load_config
@@ -562,7 +585,12 @@ async def activate_project(request: Request, slug: str):
     if not cfg.data_dir.exists():
         return JSONResponse({"error": f"Project '{slug}' not found"}, status_code=404)
 
-    response = RedirectResponse(url="/", status_code=303)
+    # Only same-site relative paths, so this cannot be turned into an open
+    # redirect. Lets the project switcher stay on the page the reviewer is on
+    # instead of dumping them back at the dashboard.
+    if not next_url.startswith("/") or next_url.startswith("//"):
+        next_url = "/"
+    response = RedirectResponse(url=next_url, status_code=303)
     response.set_cookie("active_project", slug, max_age=86400 * 365)
     return response
 

umbraaudio/web/templates/_speakers_list.html

@@ -1,5 +1,26 @@
 {% set designations = speaker_designations(request) %}
+{% set _ap = active_project(request) %}
 <div class="card">
+    {# The active project is a per-browser cookie. Two browsers could sit on
+       different books and their speaker lists are completely unrelated, which
+       made "51 need checking here, 20 there" look like a bug. Name the book
+       on the page itself, next to the counts it qualifies. #}
+    <div style="display:flex; align-items:center; gap:0.6rem; margin-bottom:0.75rem;
+                padding:0.5rem 0.7rem; background:#1a1a2e; border-left:4px solid #7c3aed; border-radius:6px">
+        <span style="color:#94a3b8; font-size:0.8rem">Reviewing</span>
+        <strong style="color:#e0e7ff; font-size:1rem">{{ _ap.name }}</strong>
+        <span style="color:#64748b; font-size:0.76rem">— this list is only this book; another browser or tab may be on a different one</span>
+        <form method="post" action="/api/projects/activate/{{ _ap.slug }}?next=/speakers"
+              style="margin-left:auto; display:flex; gap:0.35rem; align-items:center">
+            <select name="ignored" onchange="this.form.submit()"
+                    style="background:#0f3460; color:#e0e0e0; border:1px solid #374151; border-radius:4px; padding:0.25rem">
+                {% for p in list_projects() %}
+                <option value="{{ p.slug }}" {% if p.slug == _ap.slug %}selected{% endif %}>{{ p.name }}</option>
+                {% endfor %}
+            </select>
+            <noscript><button type="submit" class="btn" style="font-size:0.72rem">Switch</button></noscript>
+        </form>
+    </div>
     <div style="display:flex; justify-content:space-between; align-items:center; margin-bottom:1rem">
         <h3 style="margin:0">
             Speakers ({{ speakers|length }})