Connect Process Chat to the active Studio case

[EvenSol]

Summary

Advances the initial S3/S6 active-case handoff as the third and final PR in the bounded Studio stack.

• exposes the existing Process Chat page as an available Studio workflow
• displays the active Studio case, lifecycle state and thermodynamic package in Process Chat
• provides direct navigation among Studio home, Process Flowsheet Studio and Process Chat
• reuses the existing solved process_model session handoff; no second model adapter or simulator is introduced
• marks the active portable case dirty when Process Chat replaces/builds the live runtime model
• detaches runtime-model evidence when Process Chat resets, while preserving the portable case and unrelated Classic state
• passes bounded active-case evidence into the Process Chat system context: stable case ID, lifecycle, units, thermodynamic package, runtime-model state and provenance
• excludes the portable case body, composition, arbitrary session state and credentials from prompt evidence
• treats all user-authored metadata as untrusted data and prevents draft/dirty/failed cases from being described as solved
• adds Process Chat and the case-evidence adapter to the hosted regression and real HTTP/health gates

Stacked PR contract

• Root PR: Introduce NeqSim Studio alongside Classic #93 (automation/web-studio-shell-20260809 → main)
• Parent PR: Add shared NeqSim Studio case lifecycle #94 (automation/web-studio-case-context-20260810 → root branch)
• Exact base SHA: 73233f9c25854b5d8a992b93fd3f6f7439c894b1
• This PR base: automation/web-studio-case-context-20260810
• This PR head: automation/web-studio-process-chat-handoff-20260810
• Exact head: beefaaed69d120936d5b43441247385586a31b34

This child is not independently mergeable to main. PR #93 and then #94 must merge first; this PR must then be safely retargeted and revalidated.

The active Studio implementation stack is at its maximum of three open PRs. No fourth implementation PR may be created until an earlier PR is merged or closed.

Engineering boundary

Process Chat retains its existing Classic route, upload/build workflows and deterministic NeqSim-backed tools. This PR does not broaden chat permissions or claim that conversational changes have updated the portable flowsheet definition.

When the live chat model differs, Studio explicitly preserves:

• portable Process Flowsheet Studio schema-v4 input as the last reproducible case
• dirty lifecycle status
• an actionable reconciliation warning
• runtime-model availability/name as evidence, without serializing live Java/Python objects

The prompt adapter forwards only a whitelisted JSON-safe projection. Numeric engineering results must still come from the live model or an executed deterministic NeqSim calculation.

Validation

Passed locally on the exact source:

• Python compilation of process_chat/chat_tools.py, process_chat/studio_context.py, Process Chat and the new tests
• PYTHONPATH=. python tests/test_process_chat_studio_context.py -v — 3/3
• prior unchanged lifecycle/navigation/handoff/editor suites remained covered by the hosted cumulative gate

Hosted GitHub Actions Process Flowsheet Studio #388, run 31353304901, completed successfully on exact head beefaaed. All steps passed:

• compilation
• Studio navigation and 15 shared lifecycle tests
• Process Chat handoff plus bounded case-context tests
• Studio shell
• repeated Classic, Studio and Process Chat HTTP/health probes
• deployment-safe and warm-JVM imports
• graph editor, named streams, solver diagnostics and subflowsheets
• native multi-inlet conservation
• bounded execution

An intermediate head exposed that two inherited tests intentionally construct ProcessChatSession without __init__. The final head preserves that legacy construction path with an optional-context fallback; the complete cumulative gate then passed.

Three-repository evidence

• equinor/neqsim master advanced to 60a6bde7 with merged ProcessSystem transient snapshot/event integration (#2917), relevant future S7 evidence but not required by this S3/S6 change.
• Canonical diagram topology through #2916 remains reusable; active PFD inventory PR #2921 is owned by #1332 and is not duplicated here.
• #1332 and #2899 remain authoritative for professional PFD/P&ID/DEXPI semantics.
• EvenSol/NeqSim-Colab master remains 7cb7e5d4; the executed DEXPI safety-study notebook remains the current drawing acceptance reference. No notebook change is justified for bounded prompt metadata.

Documentation impact

Updates docs/neqsim_web_studio_roadmap.md to record bounded prompt evidence and lifecycle limitations as in stack, not merged completion. No Classic documentation, calculation behavior or portable case format changes.

Next dependency-ready tranche

The stack is full. Continue with validation, review feedback, conflict repair and integration until PR #93 or #94 is merged. After #93 merges, safely retarget #94 to main, revalidate its exact head, then advance #95 in order.