feat(server): split runtime knobs out of .env into settings.toml

.env shrinks to bootstrap values only (port, paths, log, auth, deploy
flags). The 14 admin-tunable values (retention, whisper, ollama, llm)
move to a new settings.toml with serde(default)-based per-section
defaults and an empty-prompt fallback to the code default. settings.toml
is gitignored alongside .env; settings.toml.example is the template.

This commit fixes the file layout. The server-side wiring (Config shrink,
AppState integration, consumer migration) follows separately.

server/.env.example

@@ -1,42 +1,22 @@
-# === Required (Phase 1) ===
+# Doctate operator config — bootstrap, logging, auth, deploy topology.
+# Admin-tunable values (retention, providers, prompts) live in settings.toml
+# (see settings.toml.example for the template).
 
+# Server bootstrap
 SERVER_PORT=3000
 DATA_PATH=/data
 USERS_FILE=users.toml
+
+# Logging
 LOG_LEVEL=info
 LOG_PATH=/var/log/recorder
 LOG_MAX_DAYS=90
 
-# === Optional (Phase 2+) ===
-
-# Retention
-RETENTION_AUDIO_DAYS=30
-RETENTION_TRANSCRIPT_DAYS=30
-RETENTION_DOCUMENT_DAYS=0
-
-# faster-whisper
-WHISPER_URL=http://localhost:10300
-WHISPER_TIMEOUT_SECONDS=120
-
-# Ollama
-OLLAMA_URL=http://localhost:11434
-OLLAMA_MODEL=gemma3:4b
-OLLAMA_KEEP_ALIVE=0
-
-# LLM provider (Ionos)
-LLM_URL=https://openai.inference.de-txl.ionos.com
-LLM_API_KEY=
-LLM_MODEL=
-LLM_TEMPERATURE=0
-LLM_TIMEOUT_SECONDS=180
-# Optional override of the consolidation system prompt. If unset or empty, a default is used.
-# Single line — escape newlines with \n if your shell preserves them, or put the prompt on one logical line.
-LLM_SYSTEM_PROMPT="Du bist ein medizinischer Assistent. Fasse die folgenden diktierten Abschnitte zu einem zusammenhängenden Text zusammen. Bereinigen und strukturieren, nichts hinzufügen, nichts interpretieren, keine Diagnose, keine Arztbrief-Struktur. Entferne Redundanzen. Spätere Aufnahmen haben Vorrang — Korrekturen, Nachträge und Widersprüche zugunsten der chronologisch letzten Aussage auflösen. Antworte auf Deutsch. Nur der zusammengefasste Text, keine Einleitung, kein Abschlusssatz."
-
-# Gazetteer (pre-LLM proper-name correction)
-# Directory with *.txt files, one entry per line. Blank and #-comment lines
-# are skipped. Missing directory is non-fatal — analysis runs without hints.
-VOCAB_DIR=./vocab
-
-# Session
+# Auth
 SESSION_TIMEOUT_HOURS=8
+# Set to false for plain-HTTP local dev; browsers refuse Secure cookies on http://
+COOKIE_SECURE=true
+
+# Optional filesystem resources (uncomment if used)
+# VOCAB_DIR=./vocab
+# HUNSPELL_DICT=/usr/share/hunspell/de_DE.dic