feat: add Phase 4 Logging & Tracking — inline set logging, history views

Add workout logging so users can track sets, reps, weight, and a
"felt easy?" toggle inline from the workout day view via HTMX.
Sessions auto-create on first log. History page shows past sessions
with detailed per-exercise breakdowns.

New services: WorkoutSessionService, LogService
New routes: POST /log, /log/{id}/edit, /log/{id}/delete, GET /history, /history/{id}
New templates: log_form, log_entry, session_card, log_history, session_detail
Modified: exercise_card (inline logging), nav (History link), workouts route (session context)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/templates/partials/exercise_card.html

@@ -24,5 +24,18 @@
         <p>{{ exercise.form_cues }}</p>
     </details>
 
-    <!-- Phase 4 adds: inline logging form here -->
+    <!-- Inline logging (Phase 4) -->
+    {% if active_profile %}
+    <div id="logs-exercise-{{ exercise.id }}">
+        {% if existing_logs and existing_logs[exercise.id] %}
+            {% set logs = existing_logs[exercise.id] %}
+            {% set exercise_id = exercise.id %}
+            {% set next_set = logs|length + 1 %}
+            {% include "partials/log_entry.html" %}
+        {% else %}
+            {% set next_set = 1 %}
+            {% include "partials/log_form.html" %}
+        {% endif %}
+    </div>
+    {% endif %}
 </article>

app/templates/partials/log_entry.html

@@ -0,0 +1,39 @@
+<!-- Displays logged sets for a single exercise within a session -->
+{% if logs %}
+<table>
+    <thead>
+        <tr>
+            <th>Set</th>
+            <th>Reps</th>
+            <th>Weight</th>
+            <th>Easy?</th>
+            <th>Actions</th>
+        </tr>
+    </thead>
+    <tbody>
+        {% for log in logs %}
+        <tr>
+            <td>{{ log.set_number }}</td>
+            <td>{{ log.reps_completed }}</td>
+            <td>{{ log.weight_used }}</td>
+            <td>{{ "Yes" if log.felt_easy else "No" }}</td>
+            <td>
+                <form hx-post="/log/{{ log.id }}/delete"
+                      hx-target="#logs-exercise-{{ exercise_id }}"
+                      hx-swap="innerHTML"
+                      hx-confirm="Delete this set?"
+                      style="display:inline; margin:0;">
+                    <button type="submit" class="outline secondary"
+                            style="padding:0.2rem 0.5rem; font-size:0.8rem;">
+                        Delete
+                    </button>
+                </form>
+            </td>
+        </tr>
+        {% endfor %}
+    </tbody>
+</table>
+{% endif %}
+
+<!-- Next set form -->
+{% include "partials/log_form.html" %}

app/templates/partials/log_form.html

@@ -0,0 +1,24 @@
+<!-- Inline logging form, included inside each exercise_card.html -->
+<form hx-post="/log"
+      hx-target="#logs-exercise-{{ exercise.id }}"
+      hx-swap="innerHTML"
+      style="margin-bottom:0;">
+    <input type="hidden" name="exercise_id" value="{{ exercise.id }}">
+    <input type="hidden" name="workout_day_id" value="{{ workout_day_id }}">
+    <input type="hidden" name="set_number" value="{{ next_set|default(1) }}">
+
+    <div style="display:flex; align-items:center; gap:0.5rem; flex-wrap:wrap;">
+        <small style="white-space:nowrap; opacity:0.7;">Set {{ next_set|default(1) }}</small>
+        <input type="number" name="reps" placeholder="Reps"
+               min="0" max="100" required
+               style="width:5rem; margin-bottom:0;">
+        <input type="text" name="weight" placeholder="Weight (lbs)"
+               required
+               style="width:8rem; margin-bottom:0;">
+        <label style="display:flex; align-items:center; gap:0.3rem; margin-bottom:0; white-space:nowrap;">
+            <input type="checkbox" name="felt_easy" role="switch" style="margin-bottom:0;">
+            Easy?
+        </label>
+        <button type="submit" style="margin-bottom:0; width:auto; white-space:nowrap;">Log Set</button>
+    </div>
+</form>

app/templates/partials/nav.html

@@ -27,6 +27,7 @@
     </details>
 </li>
 <li><a href="/workouts">Workouts</a></li>
+<li><a href="/history">History</a></li>
 <li><a href="/exercises">Exercises</a></li>
 <li><a href="/profiles">Profiles</a></li>
 <li><a href="/logout">Logout</a></li>

app/templates/partials/session_card.html

@@ -0,0 +1,16 @@
+<article>
+    <header>
+        <hgroup>
+            <h3>{{ day.name if day else "Unknown" }} Day</h3>
+            <p>{{ ws.date.strftime('%A, %B %d, %Y') }}</p>
+        </hgroup>
+    </header>
+    {% if ws.notes %}
+    <p>{{ ws.notes }}</p>
+    {% endif %}
+    <footer>
+        <a href="/history/{{ ws.id }}" role="button" class="outline">
+            View Details
+        </a>
+    </footer>
+</article>