feat: v0.3.0 — review welle 2 (M-4, M-5, M-6)

Three resilience and honesty fixes from the v0.2.8 review. Minor
version bump because redeploy_project and system_prune return
different strings.

M-4: trigger_build_stream now converts every non-ReadTimeout
httpx.HTTPError (ConnectError, ConnectTimeout, WriteError,
RemoteProtocolError, ...) into a SynologyError with a clear
message. Previously only ReadTimeout was handled; everything else
propagated as a raw httpx exception. redeploy_project now tracks
whether stop was actually issued and, when build_stream fails after
a successful stop, tells the user the project is in STOPPED state
and recommends start_project / retry rather than the misleading
"use stop + start separately" workaround.

M-5: _wait_for_project_running exits early on BUILD_FAILED / ERROR
(new _TERMINAL_FAILURE_STATUSES frozenset). DSM signals these
statuses within seconds of a failed image pull; the old polling
loop kept waiting up to 5 minutes for RUNNING. redeploy_project
now surfaces the terminal status with a BUILD_FAILED-specific hint
to update_image_tag.

M-6: system_prune preview now enumerates user-created networks
that have no containers attached (excluding the three built-in
networks bridge/host/none, which Docker never prunes). Previously
the preview noted "Unused networks: (not counted)" even though
SYNO.Docker.Utils/prune does delete them — users could lose
networks they had not been warned about.

Tests:
- 2 new dsm_client tests: ConnectError and RemoteProtocolError
  both raise SynologyError, not raw httpx exceptions.
- 2 new project tests: recovery hint after stop+build_stream
  failure (RUNNING case); old workaround retained for the
  STOPPED case where no stop was issued.
- 3 new polling tests: BUILD_FAILED and ERROR each trigger early
  exit; redeploy_project surfaces BUILD_FAILED with update_image_tag
  hint.
- 2 new system_prune preview tests: counts unused networks
  correctly, excludes built-ins; network-fetch failure is non-fatal.

245 tests pass. ruff check + ruff format clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,42 @@
 
 All notable changes to this project will be documented in this file.
 
+## [0.3.0] - 2026-05-18
+
+### Fixed
+
+- `DsmClient.trigger_build_stream`: broaden transport-error handling
+  (M-4). `httpx.ReadTimeout` is still treated as a success signal (the
+  request was sent; DSM is processing it server-side), but all other
+  `httpx.HTTPError` subclasses (`ConnectError`, `ConnectTimeout`,
+  `WriteError`, `RemoteProtocolError`, …) are now converted into a
+  `SynologyError` with a clear message. Previously these propagated as
+  raw httpx exceptions and left callers with a stack trace.
+- `redeploy_project`: when build_stream (or the polling step) fails
+  after the project has already been stopped, the response now
+  explicitly tells the user that the project is in `STOPPED` state and
+  must be recovered with `start_project` or another `redeploy_project`
+  call. Previously the response suggested "use stop + start
+  separately", which was misleading because stop had already happened.
+- `_wait_for_project_running`: exit the polling loop early on
+  `BUILD_FAILED` / `ERROR` (M-5). DSM signals these statuses within
+  seconds of a failed image pull; the old polling loop kept waiting up
+  to 5 minutes for `RUNNING`. `redeploy_project` surfaces the terminal
+  status with a hint to `update_image_tag` and retry when the cause is
+  `BUILD_FAILED`.
+- `system_prune` preview: count unused user-created networks alongside
+  dangling images and stopped containers (M-6). Built-in networks
+  (`bridge`, `host`, `none`) are excluded because Docker never prunes
+  them. Previously the preview noted "Unused networks: (not counted)",
+  even though the underlying `SYNO.Docker.Utils/prune` call deletes
+  them — users could lose networks they had not been warned about.
+
+### Changed
+
+- Minor version bump because `redeploy_project` and `system_prune`
+  return different strings (and `redeploy_project` returns earlier on
+  `BUILD_FAILED`). No tool signatures changed.
+
 ## [0.2.9] - 2026-05-18
 
 ### Fixed