fix: v2.0.1 — surface remote SSH file-access errors (closes #19)

Three users reported on day-one of v2.0 that SSH connections showed a
green "Connected" pill but every data view read as empty / "not running"
/ "not configured". The common thread across Docker, homelab VM, and
Ubuntu VPS setups: file-access failures on the remote that Scarf
silently swallowed into nil/empty defaults.

Stop swallowing errors
- HermesFileService gains Result-returning variants for the four
  dashboard-critical readers: loadConfigResult, loadGatewayStateResult,
  hermesPIDResult, plus readFileResult / readFileDataResult as
  primitives. Each logs os.Logger warnings on failure. Legacy nil-
  returning signatures remain as thin forwarders.
- HermesDataService.open records lastOpenError with humanized hints
  for the top three failure modes — sqlite3 not installed, permission
  denied, file not found. Each maps to concrete remediation (`apt
  install sqlite3`, "check file perms", "set Hermes data directory").

Dashboard surfaces the error
- DashboardViewModel collects errors from every loader into
  lastReadError, only on remote contexts (local skips the banner).
- DashboardView renders an orange banner above the stats with the
  specific error text, a copy-selectable detail, and a "Run
  Diagnostics…" button.

New Remote Diagnostics sheet (stethoscope icon)
- RemoteDiagnosticsViewModel runs 14 checks in one SSH round-trip via
  a pipe-delimited "KEY|STATUS|DETAIL" protocol. Covers: SSH
  connectivity, remote user/$HOME, Hermes dir existence + readability,
  config.yaml readability + actual read (distinct from just `test -e`
  which can't detect permission issues), state.db readability, sqlite3
  binary presence, sqlite3 open test, hermes binary on non-login AND
  login PATH, pgrep availability.
- Each probe row shows a targeted hint on fail (e.g. "check perms on
  ~/.hermes", "apt install sqlite3", "move PATH export from .bashrc
  to .zshenv"). A Copy Full Report button dumps plain-text output
  for GitHub issues.
- Accessible from Manage Servers (stethoscope button per row) and
  directly from the yellow pill.

Yellow "degraded" connection state
- ConnectionStatusViewModel.Status gains .degraded(reason:) between
  .connected and .error. After tier-1 `true` passes, the probe runs
  tier-2 `test -r $HOME/.hermes/config.yaml` in the same SSH round-
  trip. On tier-2 fail, pill is orange with "Connected — can't read
  Hermes state" tooltip.
- Clicking a degraded pill opens Remote Diagnostics directly. Exactly
  the symptom in #19 is now one click from a specific answer.

Auto-suggest remoteHome for non-default installs
- TestConnectionProbe.TestResult.success gains suggestedRemoteHome:
  String?. When state.db isn't found at the configured path, the
  probe also checks /var/lib/hermes/.hermes, /opt/hermes/.hermes,
  /home/hermes/.hermes, /root/.hermes — the common alternates for
  systemd services, Docker containers, and single-user VPSes — and
  surfaces the first hit as a "Use this" suggestion in Add Server.
- AddServerSheet relabels "Remote ~/.hermes override" to "Hermes data
  directory" with an explanation of when you'd use it.

README
- New "Remote setup requirements" subsection lists the four concrete
  prereqs (SSH, sqlite3, pgrep, read access to ~/.hermes).
- New "Troubleshooting remote connections" paragraph describes the
  diagnostics sheet and remoteHome auto-suggest for the two most
  common failure modes.

Releases
- releases/v2.0.1/RELEASE_NOTES.md for the GitHub release body.
- Ship via `./scripts/release.sh 2.0.1`.

Closes #19.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -42,6 +42,21 @@ Scarf 2.0 is a multi-window app. Each window is bound to exactly one Hermes serv
 
 Remote Hermes is reached over system SSH — the same `~/.ssh/config`, ssh-agent, ProxyJump, and ControlMaster pooling your terminal uses. File I/O flows through `scp`/`sftp`; SQLite is served from atomic `sqlite3 .backup` snapshots cached under `~/Library/Caches/scarf/snapshots/<server-id>/`; chat (ACP) tunnels as `ssh -T host -- hermes acp` with JSON-RPC over stdio end-to-end. Everything in the feature list below works against remote identically to local.
 
+### Remote setup requirements
+
+The remote host must have:
+
+1. **SSH access** — key-based auth via your local ssh-agent. Scarf never prompts for passphrases; run `ssh-add` once in Terminal before connecting.
+2. **`sqlite3`** on the remote `$PATH` — needed for the atomic DB snapshots. Install on the remote with `apt install sqlite3` (Ubuntu/Debian), `yum install sqlite` (RHEL/Fedora), or `apk add sqlite` (Alpine).
+3. **`pgrep`** on the remote `$PATH` — used by the Dashboard "is Hermes running" check. Standard on every distro; install `procps` if missing.
+4. **`~/.hermes/` readable by the SSH user**. When Hermes runs as a separate user (systemd service, Docker container), the SSH user needs read access to `config.yaml` and `state.db`. Either (a) SSH as the Hermes user, (b) `chmod` Hermes's home to be group-readable and add your SSH user to that group, or (c) set the **Hermes data directory** field when adding the server to point at the right location (e.g. `/var/lib/hermes/.hermes`).
+
+### Troubleshooting remote connections
+
+If the connection pill is green but the Dashboard shows "Stopped", "unknown", or empty values, the SSH user can't read the Hermes state files. Open **Manage Servers → 🩺 Run Diagnostics** (or click the yellow "Can't read Hermes state" pill in the toolbar). The diagnostics sheet runs fourteen checks in one SSH session — connectivity, `sqlite3` presence, read access to `config.yaml` and `state.db`, the effective non-login `$PATH` — and tells you exactly which one fails and why, with remediation hints for each. Use the **Copy Full Report** button to paste the full output into a bug report.
+
+For the common "Hermes isn't at the default path" case (systemd services, Docker), **Test Connection** in the Add Server sheet now probes `/var/lib/hermes/.hermes`, `/opt/hermes/.hermes`, `/home/hermes/.hermes`, and `/root/.hermes` when it can't find `state.db` at `~/.hermes/`, and offers a one-click fill if it finds any of them.
+
 ## Features
 
 Scarf mirrors Hermes's surface area through a sidebar-based UI. Sections below map 1:1 to the app's sidebar.