feat(store): SQLite schema, migrations and Danish-aware full-text search

Initial data model for verdande: users, sessions, invites, projects,
sections, tasks, labels, reminders, comments, attachments, activity
and filters, plus personal API tokens.

Search indexes a generated `fold` column alongside the original text.
FTS5's remove_diacritics does not touch ø and æ — Unicode treats them
as letters rather than accented forms — so without it a Danish user
cannot find "grøn" by typing "gron". MatchExpr quotes every term so
free text containing FTS5 operators cannot reach the query planner as
syntax.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/config/config.go

@@ -0,0 +1,142 @@
+// Package config loads verdande's settings from the environment.
+//
+// Everything is env-driven because verdande ships as a Rune: the panel hands the
+// container an environment and a /data volume, and there is nowhere to put a config
+// file that the operator would ever see.
+package config
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Config struct {
+	// BaseURL is the address verdande answers on from outside. Invite links,
+	// password resets, ICS feeds and OAuth redirects are all built from it, so it
+	// has to be the public address, not the listen address.
+	BaseURL string
+	Addr    string
+	DataDir string
+
+	SessionTTL time.Duration
+	InviteTTL  time.Duration
+	ResetTTL   time.Duration
+
+	SMTP SMTP
+
+	// TrashRetention is how long a soft-deleted task or project stays recoverable.
+	TrashRetention time.Duration
+
+	Dev bool
+}
+
+type SMTP struct {
+	Host     string
+	Port     int
+	Username string
+	Password string
+	From     string
+	// StartTLS is the common case for a self-hosted Mailcow on 587. Port 465 is
+	// implicit TLS instead and sets this false.
+	StartTLS bool
+	Insecure bool
+}
+
+// Configured reports whether outbound mail can be sent. Without a host verdande
+// still runs — it just surfaces invite links in the UI instead of mailing them.
+func (s SMTP) Configured() bool { return s.Host != "" }
+
+func Load() (*Config, error) {
+	c := &Config{
+		BaseURL:        env("VERDANDE_BASE_URL", "http://localhost:8080"),
+		Addr:           env("VERDANDE_ADDR", ":8080"),
+		DataDir:        env("VERDANDE_DATA_DIR", "/data"),
+		TrashRetention: 30 * 24 * time.Hour,
+		Dev:            envBool("VERDANDE_DEV", false),
+	}
+
+	var err error
+	if c.SessionTTL, err = envDuration("VERDANDE_SESSION_TTL", 30*24*time.Hour); err != nil {
+		return nil, err
+	}
+	if c.InviteTTL, err = envDuration("VERDANDE_INVITE_TTL", 7*24*time.Hour); err != nil {
+		return nil, err
+	}
+	if c.ResetTTL, err = envDuration("VERDANDE_RESET_TTL", time.Hour); err != nil {
+		return nil, err
+	}
+
+	port, err := envInt("VERDANDE_SMTP_PORT", 587)
+	if err != nil {
+		return nil, err
+	}
+	c.SMTP = SMTP{
+		Host:     env("VERDANDE_SMTP_HOST", ""),
+		Port:     port,
+		Username: env("VERDANDE_SMTP_USER", ""),
+		Password: env("VERDANDE_SMTP_PASS", ""),
+		From:     env("VERDANDE_SMTP_FROM", "verdande@localhost"),
+		// Port 465 is implicit TLS from the first byte; everything else negotiates
+		// with STARTTLS. An operator can still override the guess.
+		StartTLS: envBool("VERDANDE_SMTP_STARTTLS", port != 465),
+		Insecure: envBool("VERDANDE_SMTP_INSECURE", false),
+	}
+
+	c.BaseURL = strings.TrimRight(c.BaseURL, "/")
+	if c.DataDir, err = filepath.Abs(c.DataDir); err != nil {
+		return nil, fmt.Errorf("VERDANDE_DATA_DIR: %w", err)
+	}
+	return c, nil
+}
+
+// DBPath, FilesDir and BackupsDir are the three things that live on the /data volume.
+func (c *Config) DBPath() string     { return filepath.Join(c.DataDir, "verdande.db") }
+func (c *Config) FilesDir() string   { return filepath.Join(c.DataDir, "files") }
+func (c *Config) BackupsDir() string { return filepath.Join(c.DataDir, "backups") }
+
+func env(key, def string) string {
+	if v, ok := os.LookupEnv(key); ok && v != "" {
+		return v
+	}
+	return def
+}
+
+func envInt(key string, def int) (int, error) {
+	v, ok := os.LookupEnv(key)
+	if !ok || v == "" {
+		return def, nil
+	}
+	n, err := strconv.Atoi(v)
+	if err != nil {
+		return 0, fmt.Errorf("%s: %q is not a number", key, v)
+	}
+	return n, nil
+}
+
+func envBool(key string, def bool) bool {
+	v, ok := os.LookupEnv(key)
+	if !ok || v == "" {
+		return def
+	}
+	b, err := strconv.ParseBool(v)
+	if err != nil {
+		return def
+	}
+	return b
+}
+
+func envDuration(key string, def time.Duration) (time.Duration, error) {
+	v, ok := os.LookupEnv(key)
+	if !ok || v == "" {
+		return def, nil
+	}
+	d, err := time.ParseDuration(v)
+	if err != nil {
+		return 0, fmt.Errorf("%s: %q is not a duration (try 720h)", key, v)
+	}
+	return d, nil
+}