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/pages/log_history.html

@@ -0,0 +1,23 @@
+{% extends "base.html" %}
+
+{% block title %}Workout History -- SneakySwole{% endblock %}
+
+{% block content %}
+<hgroup>
+    <h1>Workout History</h1>
+    {% if active_profile %}
+    <p>History for: <strong>{{ active_profile.display_name }}</strong></p>
+    {% else %}
+    <p>No profile selected -- <a href="/profiles">select one</a></p>
+    {% endif %}
+</hgroup>
+
+{% if sessions %}
+{% for ws in sessions %}
+    {% set day = days_by_id.get(ws.workout_day_id) %}
+    {% include "partials/session_card.html" %}
+{% endfor %}
+{% else %}
+<p>No workout sessions recorded yet.</p>
+{% endif %}
+{% endblock %}