fix: install bws, isolate the private config, keep credentials out of logs

Three defects the private tier could not survive a fresh machine with.

bws was never installed. The private/bws-secrets row promised seven API
keys and shipped no way to fetch them: dotsecrets shells out to `bws
secret get`, and nothing put that binary on the box. Added as a tarball
channel with checksum verification, musl rather than gnu so it does not
pin a glibc newer than an older LTS carries, plus core/unzip as a real
@needs dependency since the release is a .zip and 24.04 minimal has no
unzip. The releases API needs filtering by tag prefix: sdk-sm is a
monorepo and `latest` usually points at a python SDK, not bws.

Both tiers rendered their config to ~/.config/chezmoi/chezmoi.toml, so
re-running the public installer overwrote the private config and took its
seven promptStringOnce answers with it. Silently -- the templates degrade
politely when data is missing, so the symptom was `git commit` not knowing
who you are, days later. The private tier now renders to private.toml and
the cmp alias carries the matching -c.

`run` echoes its argv to stderr, and the private init argv ends in
https://user:TOKEN@host -- into scrollback, any `dotup 2>log`, and any
agent transcript. Traced through redact_url instead, in both the live and
dry-run branches. The clone is also chmod -R go-rwx afterwards: it lands
at the caller umask, and .git/config stores that same credential URL.

Tests: 90 passing, 9 new covering all three.

dot_local/bin/executable_dotup

@@ -375,6 +375,10 @@ find_tool() {
 # empty, so a channel with nothing in it prints no header.
 norm() { printf '%s\n' "$*" | tr ' ' '\n' | grep . | tr '\n' ' ' | sed 's/ $//'; }
 
+# Strip userinfo from a URL for tracing: https://user:token@host/p -> https://host/p
+# Used wherever a URL that may carry a credential is about to be printed.
+redact_url() { printf '%s\n' "$1" | sed 's#://[^/@]*@#://<redacted>@#'; }
+
 run() {
 	if [ "$DRYRUN" -eq 1 ]; then printf '  + %s\n' "$*"; return 0; fi
 	printf '%s  + %s%s\n' "$DIM" "$*" "$R" >&2
@@ -570,6 +574,59 @@ install_bespoke() {
 			run_sh "${SUDO:+$SUDO }rm -rf /usr/local/go && ${SUDO:+$SUDO }tar -xzf /tmp/go.tgz -C /usr/local" \
 				|| { note_fail "$key" "tarball extract failed"; continue; }
 			run_sh "rm -f /tmp/go.tgz" ;;
+		private/bws-secrets)
+			# The Bitwarden Secrets Manager CLI. Without it the private tier
+			# fetches nothing: `dotsecrets` shells out to `bws secret get`, so
+			# this row promising seven API keys and not installing the binary
+			# was a promise it could not keep.
+			#
+			# User-level, ~/.local/bin, no sudo. It is a single static binary
+			# and the private tier is per-user by definition.
+			if have bws && [ "$DRYRUN" -eq 0 ]; then
+				say "  bws $(bws --version 2>/dev/null | awk '{print $2}') already present — leaving it"
+				continue
+			fi
+			# musl, not gnu: the gnu build pins a glibc newer than some LTS
+			# images carry, and this has to work on whatever a fresh VM is.
+			case $(uname -s) in
+			Darwin) t=macos-universal ;;
+			*)      case $(uname -m) in
+				x86_64|amd64)  t=x86_64-unknown-linux-musl ;;
+				aarch64|arm64) t=aarch64-unknown-linux-musl ;;
+				*) note_fail "$key" "no bws build for $(uname -m)"; continue ;;
+				esac ;;
+			esac
+			if [ "$DRYRUN" -eq 1 ]; then v=2.X.Y
+			else
+				# Releases are tagged per-component in this monorepo, so the
+				# `latest` endpoint points at whatever shipped last -- often a
+				# python SDK, not bws. Filter by tag prefix instead.
+				v=$(curl -fsSL 'https://api.github.com/repos/bitwarden/sdk-sm/releases?per_page=40' 2>/dev/null \
+					| sed -n 's/.*"tag_name": *"bws-v\([0-9.]*\)".*/\1/p' | head -1)
+			fi
+			[ -n "$v" ] || { note_fail "$key" "could not resolve the current bws version"; continue; }
+			b=https://github.com/bitwarden/sdk-sm/releases/download/bws-v$v
+			run_sh "curl -fsSL '$b/bws-$t-$v.zip' -o /tmp/bws.zip" \
+				|| { note_fail "$key" "download failed"; continue; }
+			# Bitwarden publishes checksums; a binary that is about to hold the
+			# key to every other credential is worth verifying.
+			if [ "$DRYRUN" -eq 0 ] && have sha256sum; then
+				if curl -fsSL "$b/bws-sha256-checksums-$v.txt" -o /tmp/bws.sums 2>/dev/null; then
+					want=$(awk -v f="bws-$t-$v.zip" '$2==f || $2=="*"f {print $1}' /tmp/bws.sums | head -1)
+					got=$(sha256sum /tmp/bws.zip | awk '{print $1}')
+					if [ -n "$want" ] && [ "$want" != "$got" ]; then
+						note_fail "$key" "checksum mismatch — refusing to install"
+						rm -f /tmp/bws.zip /tmp/bws.sums; continue
+					fi
+					[ -n "$want" ] && say "  checksum verified"
+				else
+					warn "  bws: checksums unavailable — installing unverified"
+				fi
+				rm -f /tmp/bws.sums
+			fi
+			run_sh "mkdir -p \"\$HOME/.local/bin\" && unzip -oq /tmp/bws.zip -d /tmp/bws.d && install -m 755 \"\$(find /tmp/bws.d -type f -name bws | head -1)\" \"\$HOME/.local/bin/bws\"" \
+				|| { note_fail "$key" "extract failed"; rm -rf /tmp/bws.zip /tmp/bws.d; continue; }
+			run_sh "rm -rf /tmp/bws.zip /tmp/bws.d" ;;
 		core/chezmoi)
 			# Circular by nature: dotup arrives *via* chezmoi. Present already
 			# in every case that matters; here for the one where it is not.
@@ -658,6 +715,22 @@ cmd_install() {
 PRIV_SRC=${DOTUP_PRIVATE_SRC:-${XDG_DATA_HOME:-$HOME/.local/share}/dotfiles-private}
 BWS_TOKEN=${DOTUP_BWS_TOKEN:-${XDG_CONFIG_HOME:-$HOME/.config}/bitwarden/bws-token}
 
+# The private tier gets its OWN config file, and this is load-bearing.
+#
+# chezmoi renders .chezmoi.toml.tmpl to the config path, and without -c that is
+# ~/.config/chezmoi/chezmoi.toml for BOTH tiers. The private template asks seven
+# [data] questions once (promptStringOnce) -- name, email, signing key, four
+# gitea addresses. Re-running the PUBLIC installer afterwards rewrites that same
+# file, and since the public tier's rendered config carries no [data] block, the
+# seven answers are simply gone.
+#
+# The failure is silent, which is what makes it worth a separate file rather
+# than a warning: the private templates degrade politely when their data is
+# missing -- config.local emits a comment telling you to re-run init instead of
+# failing the apply -- so the first symptom is `git commit` not knowing who you
+# are, days later, with nothing connecting it to the install you ran.
+PRIV_CFG=${DOTUP_PRIVATE_CFG:-${XDG_CONFIG_HOME:-$HOME/.config}/chezmoi/private.toml}
+
 cmd_private() {
 	rows=$(selected_private)
 	[ -n "$rows" ] || return 0
@@ -720,8 +793,28 @@ cmd_private() {
 
 	if [ "$want_repo" -eq 1 ]; then
 		if [ -n "$p_repo" ]; then
-			run chezmoi init --apply --source "$PRIV_SRC" "$p_repo" \
-				|| err "private repo init failed"
+			# NOT `run`. It echoes its whole argv to stderr, and this argv ends
+			# in https://user:TOKEN@host/... -- which would put a live git
+			# credential into terminal scrollback, any `dotup 2>log`, and any
+			# agent or CI transcript capturing the run. Trace a redacted form
+			# and execute quietly.
+			mkdir -p "$(dirname "$PRIV_CFG")"
+			if [ "$DRYRUN" -eq 1 ]; then
+				printf '  + chezmoi init --apply --source %s -c %s %s\n' \
+					"$PRIV_SRC" "$PRIV_CFG" "$(redact_url "$p_repo")"
+			else
+				printf '%s  + chezmoi init --apply --source %s -c %s %s%s\n' \
+					"$DIM" "$PRIV_SRC" "$PRIV_CFG" "$(redact_url "$p_repo")" "$R" >&2
+				chezmoi init --apply --source "$PRIV_SRC" -c "$PRIV_CFG" "$p_repo" \
+					|| err "private repo init failed"
+			fi
+
+			# The clone lands with the caller's umask, which on a stock Ubuntu
+			# is 022 -- world-readable. This tree holds ssh config, accepted
+			# keys and machine identity, and its .git/config stores the
+			# credential-bearing remote URL in plain text. On a shared or
+			# multi-user box that is readable by anyone with an account.
+			[ ! -d "$PRIV_SRC" ] || chmod -R go-rwx "$PRIV_SRC" 2>/dev/null || :
 		else err "the blob carried no PRIVATE_REPO_URL"; fi
 	fi
 	unset p_repo

dot_local/share/dotup/packages.tsv

@@ -31,6 +31,7 @@
 @needs	agents/specify-cli	core/uv
 @needs	core/mermaid-cli	core/node
 @needs	core/neovim	core/imagemagick core/mermaid-cli
+@needs	private/bws-secrets	core/unzip
 #
 # npm names carry scopes that the plugin's short name does not. `npm i -g
 # rpiv-btw` installs somebody else's package.
@@ -63,6 +64,7 @@ core	mermaid-cli	safe	-npm	-npm	mmdc — nvim renders mermaid fences with it
 core	btop	safe	btop	btop
 core	htop	safe	htop	htop
 core	ncdu	safe	ncdu	ncdu
+core	unzip	safe	unzip	unzip	the bws release ships as a .zip, and 24.04 minimal has no unzip
 core	tree	safe	tree	tree
 core	cmake	safe	cmake	cmake
 core	ninja	safe	ninja-build	ninja	package name differs from binary
@@ -116,4 +118,4 @@ virt	libvirt	invasive	libvirt-daemon-system	-	daemon + group membership
 virt	virt-manager	invasive	virt-manager	-
 @private	one password, typed after the install finishes
 private	private-repo	private	-	-	~/.local/share/dotfiles-private — agent config, ssh config
-private	bws-secrets	private	-	-	7 API keys into ~/.config/zsh/secrets.zsh
+private	bws-secrets	private	-tarball	-tarball	installs bws, then 7 API keys into ~/.config/zsh/secrets.zsh