… automatic context loading

Rewrite all OpenSpec artifacts (proposal, design, specs, tasks) to narrow
scope from general-purpose CWD tracking to project directory tracking:

- Replace `CurrentWorkingDirectory` with `ProjectDirectory` in WorkingContext
- Add standalone `set_working_directory` tool (profile-managed, audience-gated)
  instead of `set_cwd` parameter on shell_execute
- Drop shell CWD defaulting, file path resolution changes, cd detection,
  directory tree walker, and ToolExecutionContext.ToolWorkingDirectory
- Project identity files loaded from project root (no walking) and injected
  as [project-instructions] EveryTurn context layer
- Add session_dir to [session] block for agent visibility
- Unified security gate: CWD validated at set-time against audience roots
- 6 task groups, 21 tasks (down from 10 groups, 42 tasks)

Implements #595, #596.

…file loading

Sessions now track a mutable ProjectDirectory in WorkingContext that
persists across crash/restart via protobuf (tag 2). When set, the
project's identity file (.netclaw/AGENTS.md, CLAUDE.md, AGENTS.md, or
CONTEXT.md — first match wins) is automatically loaded into the system
prompt alongside global SOUL/AGENTS/TOOLING layers.

New set_working_directory tool validates the target directory exists and
is within the audience's allowed file access roots. Profile-managed so
Public/Team audiences cannot use it by default. The session actor
intercepts successful results (gated by Path.IsPathRooted) to update
WorkingContext and re-assemble the system prompt.

Also adds session_dir to the [session] context block so the agent knows
its full session directory path without inferring from media_dir.

ISystemPromptProvider.GetSystemPrompt() now accepts an optional
projectDirectory parameter — the provider remains stateless, avoiding
race conditions across concurrent session actors sharing the DI
singleton.

Implements openspec change: session-cwd-tracking

…abilities

Patches GHSA-g94r-2vxg-569j (OpenTelemetry.Api), GHSA-mr8r-92fq-pj8p and
GHSA-q834-8qmm-v933 (OpenTelemetry.Exporter.OpenTelemetryProtocol). Also
pins OpenTelemetry.Api explicitly to override the transitive 1.9.0 pulled
by Akka.Hosting.

…t vulnerabilities"

This reverts commit b271a81.