docs: enrich CHANGELOG and add Contributors section for 1.4.0

Audit pass against the actual commit messages between v1.3.0 and
v1.4.0 turned up several substantive items the initial CHANGELOG
under-described or omitted entirely.  Fix-forward expansion plus a
Contributors section recognizing external contributors.

Added detail / coverage:

- New "Server compatibility layer for local model servers" entry —
  the vLLM / llama.cpp profiles + admin UI fields shipped in #352
  alongside the capabilities passthrough; previously buried under one
  bullet.
- Per-call plan/task model selection split into three sub-bullets
  (backend split, runtime configurability without restart via
  ConfigStore admin tab, per-call override) — three PRs that build on
  each other deserve to be discoverable independently.
- Opus 4.7 entry expanded with 1M ctx / 128K output, the new
  thinking_display capability field, xhigh effort level, and admin
  dropdown updates.
- Dashboard composer note: tab-bar `+` modal also gained the paperclip
  + chip strip + first-message field.
- Slack adapter: explicit "session recovery via persisted recoverable
  route keys" — ops-relevant promise for restart behaviour.
- pgbouncer swap: helm chart link + ports updates noted.
- Provider capabilities entry: defensive shallow-copy + chat_template
  deep-merge follow-ups.

New Fixed entries:

- Cross-user attachment-fetch hardening (get_attachment_content
  scopes by user_id).
- Attachment-list DoS guard on /v1/api/send.
- Bounded LRU for upload locks.
- 3.12 CI deadlock root-cause writeup (asyncio.Lock vs Starlette
  TestClient loop teardown).

New SDK entry:

- PlanResolvedEvent type + guard, dispatched cross-client when one
  client resolves a plan so others dismiss in sync.

New Operational subsection:

- vendor-js workflow now auto-downloads hls.js for future Renovate
  bumps so they're merge-ready without manual file fetches.

Contributors:

- Recognise @daoxley (Slack adapter, #355) and @pizzaandcheese
  (pgbouncer swap, #353) — the two external contributors with
  meaningful net-new work in this release — plus the Renovate bot.
- Pointer to channel-attachment ingest as the headline 1.4.1 feature
  for would-be contributors.

CHANGELOG.md

@@ -52,11 +52,13 @@ existing 1.3.x database.  Both are additive; no data loss.  See
   SDKs auto-generate `ws_id` client-side so cluster-routed callers can
   bind the body to the owning node before it lands. (#362)
 - **Slack channel adapter** (Socket Mode) — mirrors the Discord adapter:
-  per-user channel sessions via configurable slash command, DM routing,
-  SSE event consumption, tool approval buttons (with per-user owner
-  enforcement), plan-review approve / request-changes modal,
-  notification reply routing back into the workstream, session recovery
-  after restart.  Install with `pip install 'turnstone[slack]'`. (#355)
+  per-user channel sessions via configurable slash command, DM routing
+  without slash command, SSE event consumption, tool approval buttons
+  with per-user owner enforcement, plan-review approve / request-changes
+  modal, notification reply routing back into the workstream, and
+  session recovery after restart via persisted recoverable route keys
+  (the bot re-subscribes to existing Slack-routed workstreams when it
+  comes back).  Install with `pip install 'turnstone[slack]'`. (#355)
 - **Console admin UX support for Slack** — channel-link modal offers
   Slack alongside Discord; skill notify-on-complete forms expose a
   per-row channel-type dropdown (and no longer hardcode `discord`);
@@ -64,16 +66,59 @@ existing 1.3.x database.  Both are additive; no data loss.  See
   theme-aware tokens (`--discord` / `--slack`) so light theme passes
   WCAG AA. (#365)
 - **Per-call plan/task model selection** — `plan_model` and `task_model`
-  are now distinct from the conversation model and from each other, with
-  configurable reasoning effort per agent.  `ConfigStore` admin tab in
-  the console UI lets operators set defaults; per-call overrides
-  available via the `plan_agent` / `task_agent` tools. (#360, #361)
+  are now distinct from the conversation model and from each other,
+  with configurable reasoning effort per agent.  Three layers:
+  - **Backend split** (`#54dd557`) — `ModelRegistry` gains `plan_model`,
+    `task_model`, `plan_effort`, `task_effort`; per-kind overrides win
+    over the legacy `agent_model`, which still works as the single-knob
+    fallback.  `resolve_agent_alias(kind)` and `resolve_agent_effort(kind)`
+    centralise resolution.  Loader validates effort against
+    `{none, minimal, low, medium, high, xhigh, max}` with warn+drop on
+    typos.
+  - **Runtime configurability** (`#360`) — `ConfigStore` admin tab in
+    the console UI lets operators switch alias and reasoning effort per
+    agent **without restarting**.  `INHERIT_EMPTY_LABEL_KEYS` shows
+    `(inherit)` for empty effort selections — distinct from the literal
+    `none` choice which actually disables reasoning.  Routing overrides
+    apply on `/v1/api/_internal/config-reload` (admin saves), and
+    `model-reload` short-circuits when nothing changed so no in-flight
+    clients churn.
+  - **Per-call override** (`#361`) — the calling LLM can pass
+    `model="<alias>"` to `plan_agent` or `task_agent` to override the
+    operator-configured per-kind model for that one invocation.  Tool
+    descriptions list the live registered aliases (refreshed when the
+    operator hits "sync to nodes"), so the LLM always sees current
+    options.  Bad aliases return a corrective error dict listing the
+    available choices.  No whitelist — cost control is intentionally
+    ceded to the model.  Plan-retry path reuses the alias so coaching
+    reflects real model behaviour. (#360, #361)
 - **Provider capability passthrough** — resolved per-model capabilities
-  (vision support, reasoning support, native web search, etc.) flow
-  through to provider clients so feature gating no longer relies on
-  string matching.  Server companion published in the same change. (#352)
-- **Claude Opus 4.7 support** — provider capabilities, tokenizer
-  awareness, and adaptive thinking semantics. (#357 — also in 1.3.1)
+  (vision, reasoning, native web search, thinking_mode, token_param,
+  etc.) flow through to provider clients via a new `capabilities`
+  parameter on `create_streaming` / `create_completion`, so feature
+  gating no longer relies on string matching and admin-UI / config.toml
+  overrides actually reach the provider.  Defensive shallow-copy in
+  `_finalize_extra_body` so callers reusing the same dict across models
+  are safe; deep-merge of `chat_template_kwargs` so operators can
+  extend instead of silently overwriting. (#352)
+- **Server compatibility layer for local model servers** — vLLM and
+  llama.cpp profiles suggest the right thinking mode and per-server
+  workarounds (`skip_special_tokens` for vLLM, `reasoning_format` for
+  llama.cpp) during model detection.  Admin UI gains structured fields
+  for server type, thinking mode, and extra body params, hidden for
+  non-local providers (openai/anthropic/google).  New `thinking_param`
+  text field surfaces the alias name (default `enable_thinking`;
+  Granite/DeepSeek use `thinking`).  Verified end-to-end against real
+  vLLM (Gemma 4 31B) and llama.cpp (Gemma 4 E4B) servers. (#352)
+- **Claude Opus 4.7 support** — `claude-opus-4-7` capability entry
+  (1M ctx, 128K output, adaptive thinking, `supports_temperature=False`,
+  `thinking_display=summarized`).  New `ModelCapabilities.thinking_display`
+  field — Opus 4.7 omits thinking by default but always sends summarized
+  blocks back through the provider boundary.  Adds `xhigh` effort level
+  to the global mapping and to Opus 4.7's `effort_levels`; admin-console
+  skill-template dropdowns gained `xhigh` and `max` options.  Reasoning
+  effort label capitalization aligned across all console dropdowns.
+  (#357 — also in 1.3.1)
 - **Dashboard composer refactor** — unified single-flow create from the
   per-node dashboard.  Multi-line textarea + collapsible Options panel
   (model / judge / skill) + paperclip + drag-drop / paste-image + chip
@@ -84,7 +129,9 @@ existing 1.3.x database.  Both are additive; no data loss.  See
   separate modal.  Options panel state persists in `localStorage`;
   active non-default selections render as an inline summary chip beside
   the Options button; drag-over shows an explicit "Drop to attach"
-  overlay. (#362, #366)
+  overlay.  The tab-bar `+` new-workstream modal also gained a paperclip
+  + chip strip + first-message field so the same flow is reachable from
+  both entry points. (#362, #366)
 - **Workstream attachments — orphan reservation sweep** — periodic
   background sweep clears `reserved_for_msg_id` on rows whose
   `reserved_at` exceeds a 1-hour threshold, self-healing reservations
@@ -116,9 +163,11 @@ existing 1.3.x database.  Both are additive; no data loss.  See
   show a `…and N more (preview truncated)` suffix. (#365)
 - **PostgreSQL deployment image** swapped from `bitnami/pgbouncer` to
   `edoburu/pgbouncer` to track upstream releases and reduce image size.
-  No config changes required for typical deployments; review your helm
-  values if you depend on `bitnami`-specific environment variable
-  conventions. (#353)
+  Environment variables remapped to the edoburu naming, ports updated
+  to match documented expectations, and the Kubernetes Helm Chart link
+  in the deployment docs now points at the same container.  Review
+  your helm values if you depend on `bitnami`-specific environment
+  variable conventions. (#353)
 
 ### Fixed
 
@@ -149,6 +198,28 @@ existing 1.3.x database.  Both are additive; no data loss.  See
   `.scope-slack` first shipped with raw hex that failed WCAG AA on
   light theme (1.8:1 / 2.4:1).  Theme-aware `--discord` / `--slack`
   tokens with proper light variants now pass. (#365)
+- **Cross-user attachment fetch hardening** — `get_attachment_content`
+  now scopes the row by `user_id` in addition to `ws_id`, so an
+  unowned workstream can't be a vector for cross-user blob fetches via
+  attachment-id guessing. (#356)
+- **Attachment-list DoS guard** — `/v1/api/send` rejects
+  `attachment_ids` lists longer than the per-(ws, user) pending cap
+  with a 400, preventing hostile clients from blowing up the storage
+  `IN (...)` clause. (#356)
+- **Bounded LRU for upload locks** — the per-(ws, user) attachment
+  upload-lock map now evicts the oldest unlocked entries past a soft
+  cap, so the in-process map can't grow unbounded on long-running
+  nodes. (#356)
+- **3.12 CI deadlock on attachment uploads** — the upload-lock was
+  initially an `asyncio.Lock`, but Starlette's `TestClient` runs each
+  request on a fresh anyio task / event loop, so the cached lock's
+  `_waiters` bound to the first loop and a later request would block
+  on a Future from a closed loop (silent deadlock).  Switched to
+  `threading.Lock` — loop-agnostic, and the critical section is one
+  COUNT + one INSERT.  Same root cause is reproducible against any
+  Starlette TestClient harness on Python ≥ 3.10; 3.12 surfaces it
+  more often.  Production users on a single event loop weren't
+  affected, but the test environment was. (#356)
 
 ### Security
 
@@ -194,6 +265,40 @@ Python + TypeScript clients gained:
 - Refusal of `attachments + target_node` combination at the SDK
   boundary (the multipart routing layer doesn't honor `target_node`,
   so silently picking the wrong node is now an explicit error)
+- `PlanResolvedEvent` SSE event with type guard, dispatched when one
+  client (e.g. mobile) resolves a plan so other connected clients can
+  dismiss their plan-approval modal in sync.  Available in both the
+  Python and TypeScript SDKs. (#87a9af1)
+
+### Operational
+
+- **CI vendor-asset auto-download covers `hls.js`** — the
+  `vendor-js.yml` workflow previously only iterated katex/hljs/mermaid,
+  so Renovate bumps for `hls.js` failed the wheel-completeness check
+  and required manual file downloads.  Detection loop now includes
+  `hls`, so future Renovate bumps are merge-ready without intervention.
+  (#354)
+
+### Contributors
+
+Thanks to the people who made this release happen — especially the
+external contributors who picked up substantial pieces of work:
+
+- **[@daoxley](https://github.com/daoxley)** — designed and shipped
+  the Slack channel adapter (Socket Mode bot, per-user sessions,
+  approvals, plan-review, notification routing).  Major new feature
+  surface in #355.
+- **[@pizzaandcheese](https://github.com/pizzaandcheese)** — replaced
+  the deprecated bitnami pgbouncer image with the edoburu image,
+  remapped environment variables, ports, and helm chart references.
+  Operationally important for anyone running our reference Postgres
+  deployment (#353).
+- Renovate kept dependencies and the JS vendor tree current via
+  several automated bumps.
+
+If you're interested in contributing, channel-attachment ingest from
+Discord + Slack is the headline 1.4.1 feature and a solid place to
+start — see the open issues on GitHub or open one to scope a piece.
 
 ## [1.3.1]