agent: skip planning for casual greetings + strengthen DIRECT shortcut in Phase 1 ...

- Add fast _is_casual_message heuristic in navi/core/agent.py. Greetings and
  social chat (e.g. 'привет', 'как дела', 'hi', 'thanks') bypass planning even
  on the first session message, unless planning_mandatory is enabled.
- Strengthen Phase 1 planning prompt in navi/core/planning.py: explicitly
  require DIRECT output for greetings, simple questions, and one-step
  instructions.
- Fix broken ContextCompressed import in navi/core/compressor.py.
- Add unit tests covering the new heuristic and DIRECT prompt.

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

Phase 2: Dual-write with is_context/is_display flags on Message ...

- Message model gets is_context and is_display bools
- PgSessionStore.save() writes flags directly to session_messages
- Agent sets is_context=False on display-only messages, is_display=False on context-only
- Planning: plan context msg is_display=False, plan marker is_context=False
- Compression: summarized messages get is_context=False, summary added to messages with is_display=False
- Tests updated for extra user display+context messages per turn

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

Fix planning: change plan-follow-up role from system to user ...

After injecting the plan as an assistant message into session.context,
the previous code appended a system message saying "Plan is ready.
Execute it now..."  Many instruct-tuned models treat their own
assistant message as a completed response, and a trailing system
instruction is easy to ignore.

Changing the follow-up to role="user" makes the model see:
  assistant: plan
  user: "Execute this plan..."
which obligates the model to produce a new assistant response —
the tool-calling execution phase.

The follow-up message is appended only to session.context (LLM
context) and never to session.messages, so it is invisible in the
chat UI.

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

Enhance native toolset and add persistent KV store ...

- Add PostgreSQL-backed KvStore (navi/store/) for session-scoped data.
- Migrate todo and scratchpad from in-memory dicts to KvStore.
- Filesystem: add copy, grep, diff actions; compress description.
- CodeExec: remove language param, expose working_dir in schema.
- ImageView: resize to 1024px JPEG + Content-Type guard for URLs.
- Memory list: return distinct categories instead of all facts.
- SSH: add scp action with upload/download support.
- Update CLAUDE.md (Postgres-only), docs/tools.md, add docs/store.md.
- Fix agent/planning/context_builder async signatures for todo helpers.

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

Refactor: move tool helper modules into _internal subpackage ...

Moves non-tool infrastructure out of navi/tools/ root so that only
actual tool classes live there:

  base.py           → _internal/base.py
  loader.py         → _internal/loader.py
  middleware.py     → _internal/middleware.py
  logging_middleware.py → _internal/logging_middleware.py
  _time_parser.py   → _internal/time_parser.py

All imports updated across core/, api/, mcp/, tools/, and tests/.
No proxy files remain in navi/tools/ root.

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

Clarify knowledge persistence prompts

Integrate proactive knowledge capture into planning and persona ...

- Phase 1 planning: add KNOWLEDGE CAPTURE section to prompt
- Phase 3 planning: add knowledge persistence rule with target selection
- Persona: add "search before save" deduplication instruction
- MCP gnexus-book: add persistence guidance for discovered facts

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

Add deterministic line-based file editing (edit_lines), rating UI fix, and session refresh ...

- filesystem.py: add edit_lines action (deterministic line ops via operations array)
           + numbered param for read (1-based line numbers in output)
           + clarify four editing modes in tool description
- chat.js: fix rating IDs for streaming messages (assign h_ ID on stream_end)
- SessionList.vue: mobile pull-to-refresh with PTR_THRESHOLD=80
- AppSidebar.vue: desktop refresh button next to Conversations header
- planning.py: knowledge source assessment in Phase 1
- debug panel: MCP servers tab + resolved tools per profile
- NAVI.md: reposition as neutral quick-reference

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

Improve 3D modeling validation prompts

Open artifact links externally on Android

Extract PlanningEngine, ContextBuilder, ToolExecutor from agent.py ...

- navi/core/planning.py: new 3-phase planning pipeline (~390 lines)
- navi/core/context_builder.py: system prompt caching, memory/context injection, goal anchoring (~160 lines)
- navi/core/tool_executor.py: tool execution with middleware chain (~150 lines)
- navi/core/agent.py: reduced from ~1420 to ~770 lines; delegates to extracted classes

All compilation verified.

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