Rebuild dotfiles as one branch with per-host layers

Replaces the previous repo, which had split into two histories that never
met (mainframe on a dead GitLab remote, the laptops on Gitea) with 146
dirty files across three machines and the NAS never enrolled at all.

Branch-per-machine is gone. One main, with host differences expressed as
small files under hosts/<hostname>/ rather than as branches, so there is
nothing to merge. The reconciled zsh layer reduces 15-33 line forks to
1-7 effective lines per host; distro differences (oh-my-zsh prefix,
syntax-highlighting path, fd vs fdfind) are probed in common/ instead.

Fresh history: the old one carried six plaintext credentials, 45 MB of
mail caches, browser caches and vendored binaries. 5,096 tracked files
and 144 MB become 462 files and 2.6 MB. The .gitignore is now an
allowlist, which is what keeps that true.

Root cause of the rot: ~/.local/bin was a symlink to scripts/ with GOPATH
inside it, so every go install wrote into version control (2.2 GB on the
work laptop). PATH now points at the repo instead of the reverse.

Also: Hyprland replaces sway and is sourced in two halves so $browser is
defined before use; singleton automations carry ConditionHost= alongside
host-layer-only placement; ddns moves from cron to a guarded timer;
package manifests and pkg-snapshot/pkg-restore replace the X11-era
install_scripts/; networkmanager-dmenu added to system76 (the binding
always existed, the package never did).

hosts/mainframe/sbin/backup-db-dump

@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+#
+# Dump every database to a consistent on-disk file so restic snapshots a
+# restorable copy rather than a live file mid-write.
+#
+# Design notes:
+#
+#  * SQLite dumps run from the HOST, not inside the containers. Vaultwarden
+#    and SFTPGo images ship no sqlite3 binary and traggo is distroless with no
+#    shell at all, so `podman exec` cannot work there. The DB files are on host
+#    bind mounts and `.backup` is safe against a live writer.
+#
+#  * The Immich dump goes to the NFS mount (-> the NAS), NOT /var/backups.
+#    Immich's blobs live on the NAS and its database on mainframe; writing the
+#    dump beside the blobs means one NAS restic snapshot captures both halves.
+#    A database restored against missing photos is not a restore.
+#
+#  * .env is PARSED, never sourced. OPENVPN_PASSWORD contains characters that
+#    break `.` under bash, and quoting it changes what podman-compose passes to
+#    the container -- so the file is left exactly as compose expects and read
+#    with a plain parser instead.
+#
+#  * Every file is written to .tmp and renamed, so a concurrent backup never
+#    snapshots a truncated dump.
+
+set -euo pipefail
+umask 077
+
+DEST=/var/backups/db
+IMMICH_DEST=/home/connor/photo/immich/backups
+ENVFILE=/home/connor/.env
+
+log() { printf '%s backup-db-dump: %s\n' "$(date -Is)" "$*"; }
+env_get() { sed -n "s/^$1=//p" "$ENVFILE" | head -1 | sed -E "s/^'(.*)'\$/\1/; s/^\"(.*)\"\$/\1/"; }
+
+mkdir -p "$DEST"
+IMMICH_DB_USERNAME=$(env_get IMMICH_DB_USERNAME)
+HEDGEDOC_DB_ROOT_PASSWORD=$(env_get HEDGEDOC_DB_ROOT_PASSWORD)
+[ -n "$IMMICH_DB_USERNAME" ] || { log "ERROR: could not read IMMICH_DB_USERNAME"; exit 1; }
+
+# --- Postgres (Immich) -----------------------------------------------------
+if mountpoint -q /home/connor/photo && mkdir -p "$IMMICH_DEST" 2>/dev/null; then
+    tgt="$IMMICH_DEST"
+else
+    log "WARN: /home/connor/photo not mounted; writing immich dump locally instead"
+    tgt="$DEST"
+fi
+log "immich postgres -> $tgt"
+podman exec connor_immich_db_1 sh -c "pg_dumpall -U '$IMMICH_DB_USERNAME'" \
+    | zstd -q -o "$tgt/immich-pgdump.sql.zst.tmp"
+mv -f "$tgt/immich-pgdump.sql.zst.tmp" "$tgt/immich-pgdump.sql.zst"
+
+# --- MariaDB (HedgeDoc) ----------------------------------------------------
+log "hedgedoc mariadb"
+podman exec connor_hedgedocdb_1 sh -c \
+    "mariadb-dump --single-transaction -u root -p'$HEDGEDOC_DB_ROOT_PASSWORD' hedgedoc" \
+    | zstd -q -o "$DEST/hedgedoc.sql.zst.tmp"
+mv -f "$DEST/hedgedoc.sql.zst.tmp" "$DEST/hedgedoc.sql.zst"
+
+# --- SQLite ----------------------------------------------------------------
+for spec in \
+    "vaultwarden:/home/connor/data/bitwarden/db.sqlite3" \
+    "gitea:/home/connor/data/gitea/gitea/gitea.db" \
+    "traggo:/home/connor/data/traggo/traggo.db" \
+    "sftpgo:/home/connor/docs/sftpgo.db" \
+    "shanty:/usr/local/shanty/shanty.db" \
+; do
+    name=${spec%%:*}; path=${spec#*:}
+    if [ ! -f "$path" ]; then log "WARN: $name db missing at $path, skipping"; continue; fi
+    log "$name sqlite"
+    rm -f "$DEST/$name.sqlite3.tmp"
+    sqlite3 "$path" ".backup '$DEST/$name.sqlite3.tmp'"
+    # Verify before promoting. A corrupt dump that looks like a file is worse
+    # than a missing one: it restores without complaint.
+    if [ "$(sqlite3 "$DEST/$name.sqlite3.tmp" 'pragma integrity_check;' 2>&1 | head -1)" != "ok" ]; then
+        log "ERROR: $name failed integrity_check, keeping previous dump"
+        rm -f "$DEST/$name.sqlite3.tmp"; continue
+    fi
+    mv -f "$DEST/$name.sqlite3.tmp" "$DEST/$name.sqlite3"
+done
+
+log "done"