chore(release): finalize 2.4.0 docs and homepage updates

Polish the 2.4.0 release communication by updating changelog language,
adding blog and release-note docs, linking them from the README homepage,
and syncing the lockfile package version.

Author: rithulkamesh

CHANGELOG.md

@@ -11,20 +11,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- **Distributed runtime extension layer** — Added `devsper.distributed` package with controller and worker-runtime wrappers for clean orchestration composition.
-- **Agent pool** — Added `runtime/agent_pool.py` with reusable, worker-aware concurrent agent leasing (`acquire_agent`, `release_agent`, `run_agent`, `run_parallel`).
-- **Model router (runtime layer)** — Added `runtime/model_router.py` for planning/reasoning/validation model routing with fallback chains.
-- **Speculative planner (runtime layer)** — Added `runtime/speculative_planner.py` to predict and stage speculative successor tasks.
-- **Runtime HITL manager** — Added `runtime/hitl.py` for pause/resume and explicit human-input request lifecycle handling.
-- **Execution graph upgrades** — Extended runtime execution graph with worker assignment metadata and distributed lineage tracking.
+- **Distributed runtime extensions** — Added modular runtime components for distributed orchestration: `AgentPool`, `ModelRouter`, `SpeculativePlanner`, `HITLManager`, `ExecutionGraph` worker assignment tracking, plus distributed wrappers (`distributed/controller.py`, `distributed/worker_runtime.py`).
+- **Runtime architecture documentation** — Expanded runtime docs with distributed architecture, worker/controller lifecycle, speculative execution flow, and HITL lifecycle details.
+- **Tool execution hardening** — Upgraded runtime tool runner with bounded parallelism, dependency-aware batching, per-call timeout isolation, and cancellation support.
 
 ### Changed
 
-- **Executor composition** — Runtime executor now integrates AgentPool, ModelRouter, speculative planning hooks, and distributed assignment tracking while preserving default behavior.
-- **Task runner routing** — Task execution now supports pool-backed agent execution, scoped model routing, and fallback chain handling.
-- **Tool execution control** — Runtime ToolRunner now supports bounded concurrency, dependency-aware batching, per-call timeout, cancellation, and structured results.
-- **Event backpressure handling** — Runtime event stream now uses bounded queues with controlled overflow behavior.
-- **Runtime docs** — Updated runtime architecture docs in `devsper/README.md` with distributed flow, worker/controller lifecycle, and HITL/speculative execution details.
+- **Executor orchestration** — Runtime executor now supports agent-pool-backed execution, model routing integration, speculative follow-up scheduling hooks, and improved cancellation/backpressure behavior.
+- **Prompt/token efficiency** — Tool schema injection in agent prompts was compressed to reduce runtime token overhead in tool-enabled turns.
+- **Homepage and release communication** — Updated README homepage with v2.4.0 release CTA and an architecture upgrade blog entry for this release.
 
 ## [2.3.0] — 2026-03-30
 

README.md

@@ -311,6 +311,10 @@ Full docs (with versioning and dark mode): **[docs.devsper.com](https://docs.dev
 | [Contributing](CONTRIBUTING.md) | Setup, testing, PR guidelines |
 | [FAQ](https://docs.devsper.com/docs/faq) | Common questions |
 
+### Blog
+
+- [Distributed Runtime Upgrade (v2.4.0)](devsper/docs/blog/2026-03-31-runtime-2-4-0.md)
+
 ---
 
 ## Attribution & Credits

devsper/docs/architecture/execution-model.md

@@ -5,3 +5,8 @@ The canonical execution model document lives under **docs**:
 **See: [docs/architecture/execution-model.md](../../../docs/architecture/execution-model.md)**
 
 That document is the source of truth for DAG execution, task state machine, HITL clarification (single-node and distributed, including Rust worker), bus topics, TUI lifecycle, and headless mode.
+
+For the 2.4.0 distributed runtime upgrade summary, see:
+
+- `devsper/docs/releases/2.4.0.md`
+- `devsper/docs/blog/2026-03-31-runtime-2-4-0.md`

devsper/docs/blog/2026-03-31-runtime-2-4-0.md

@@ -0,0 +1,89 @@
+# Devsper Runtime 2.4.0: Distributed Architecture Upgrade
+
+Date: 2026-03-31
+Version: 2.4.0
+
+## Why this release
+
+Devsper has supported distributed execution paths for a while, but runtime internals needed cleaner extension points for worker-local execution, model routing, and fault-tolerant orchestration. Version 2.4.0 introduces those extension layers while preserving existing behavior.
+
+## What changed
+
+### 1) Agent Pool for worker-local reuse
+
+`runtime/agent_pool.py` introduces pooled agent lifecycle management:
+
+- `acquire_agent()`
+- `release_agent()`
+- `run_agent()`
+- `run_parallel()`
+
+This reduces repeated setup overhead and enables consistent worker-aware agent execution.
+
+### 2) Model Router for task-aware selection
+
+`runtime/model_router.py` routes:
+
+- planning-oriented tasks to planning models
+- reasoning-heavy tasks to primary reasoning models
+- validation/review tasks to cheaper validation models
+
+Fallback model chains are supported when primary execution fails.
+
+### 3) Speculative planner hooks
+
+`runtime/speculative_planner.py` adds lightweight speculative execution planning:
+
+- predicts likely successor tasks
+- marks/schedules speculative tasks early
+- cancels speculative branches when dependencies fail
+
+### 4) Runtime HITL manager
+
+`runtime/hitl.py` formalizes pause/request/resume behavior:
+
+- pause task
+- emit human input request event payload
+- wait for response or timeout
+- resume or fail according to policy
+
+### 5) Distributed wrappers
+
+New distributed modules provide composable extension points:
+
+- `distributed/controller.py`
+- `distributed/worker_runtime.py`
+
+The controller coordinates workers and assignment strategy; worker runtime executes agents/tools locally.
+
+### 6) Execution graph extension
+
+`runtime/execution_graph.py` now tracks distributed assignment metadata:
+
+- worker id
+- assignment timestamp
+- lineage visibility for distributed tracing
+
+## Operational benefits
+
+- Better runtime modularity for distributed deployments
+- Cleaner separation between coordination and local execution
+- Improved cancellation/backpressure behavior
+- More predictable model routing and fallback handling
+- Better traceability of worker assignment in execution graphs
+
+## Upgrade notes
+
+1. Upgrade package:
+
+```bash
+pip install -U devsper
+```
+
+2. Review:
+
+- `CHANGELOG.md`
+- `devsper/README.md`
+- `devsper/docs/releases/2.4.0.md`
+
+3. Validate with your current distributed setup using existing controller/worker paths first, then adopt the new runtime modules incrementally.

devsper/docs/releases/2.4.0.md

@@ -0,0 +1,40 @@
+# Release Notes: 2.4.0
+
+## Highlights
+
+- Distributed runtime architecture extensions
+- Agent pool support for worker-local execution
+- Task-aware model routing with fallback chains
+- Speculative planner hooks for successor prediction
+- Runtime HITL manager for pause/request/resume flow
+- Execution graph worker assignment tracking
+
+## New modules
+
+- `runtime/agent_pool.py`
+- `runtime/model_router.py`
+- `runtime/speculative_planner.py`
+- `runtime/hitl.py`
+- `distributed/controller.py`
+- `distributed/worker_runtime.py`
+
+## Runtime updates
+
+- `runtime/executor.py` now integrates:
+  - agent pool execution path
+  - model router integration
+  - speculative execution hooks
+  - improved cancellation behavior
+
+- `runtime/task_runner.py` now supports routed model execution with fallback chains.
+
+- `runtime/execution_graph.py` includes distributed assignment metadata.
+
+## Docs and homepage updates
+
+- `README.md` homepage now includes a v2.4.0 release CTA and blog links.
+- Added this release note and architecture blog post for rollout communication.
+
+## Compatibility
+
+This release extends existing architecture and keeps current runtime paths intact. Existing workflows should continue to run without migration changes.