refactor!: remove web companion (no user usecase per 2026-07-23 review)

Catches up a rollback that was decided and archived on 2026-07-23 but
never reached this repository: the companion usecase audit removed the
static web_companion/ PWA viewer, yet the change only happened on the
local working copy. No git clone of this project existed on the host that
ran the audit, so nothing was ever committed or pushed - the companion
stayed public here while the audit reported it as removed.

The viewer was a read-only view of an exported devcenter-workspace-v1.json
with no actionable use - the negative pattern the audit set out to remove.
The export itself stays (see EXPORTFORMAT.md).

Also in this commit:
  - README.md / llms.txt: dropped the remaining companion references
    (CHANGELOG.md keeps its entries - those are release history)
  - PORTIERUNGSPLAN.md: added with the ENTFERNT record the audit requires,
    including the archive path
  - .gitignore: ignore LOCK*.txt (local multi-agent lock files)

Archive: C:\_Local_DEV\companion_removals_20260723\REL-PUB_DevCenter_SUITE
Verified: compileall clean, unittest discover OK, 114 pytest tests pass,
no web_companion reference left outside CHANGELOG.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VKPLKAfmZnnoNHDffUdSyc

Author: Lukas Geiger

.gitignore

@@ -95,3 +95,6 @@ DECISIONS.md
 PORTIERUNGSPLAN.md
 TODO.md
 DONE.md
+
+# Lokale Agenten-Locks (LOCK-System)
+LOCK*.txt

README.md

@@ -44,7 +44,7 @@ DevCenter consists of a highly capable local Desktop Application and a lightweig
 - **Static analysis built in:** method/class detection, complexity checks, import analysis, TODO/FIXME detection and encoding repair helpers.
 - **Build and release helpers:** PyInstaller wrapper, icon conversion, third-party license collection, release notes and export planning.
 - **Optional AI assistant:** Claude/Anthropic integration is opt-in and uses local settings, keyring or environment variables.
-- **Companion-ready export:** writes a redacted `devcenter-workspace-v1.json` for the static `web_companion/` PWA viewer.
+- **Redacted workspace export:** writes a redacted `devcenter-workspace-v1.json` (see `EXPORTFORMAT.md`).
 
 ## Quick Start
 
@@ -92,10 +92,6 @@ build_exe.bat
 - Import/export support for reproducible setups
 - Theme and window state restored on restart
 
-### Web Companion
-- Static `web_companion/` PWA viewer for redacted workspace exports
-- Installable, offline-capable, no backend required
-
 ## Installation
 
 Requirements: Python 3.10+, Windows 10/11 (primary), Linux/macOS (experimental)
@@ -179,7 +175,6 @@ DevCenter/
 │   │   ├── ai_assistant/     # Claude API integration
 │   │   └── filemanager/      # File index, backup sync
 │   └── gui/                  # Main window, panels, dialogs
-├── web_companion/            # Static PWA viewer for workspace exports
 └── tests/                    # Unit tests
 ```
 

llms.txt

@@ -26,7 +26,6 @@ Privacy and safety:
 - `README.md`: user-facing overview, screenshots, installation and feature list.
 - `PRIVACY_POLICY.md`: privacy scope for local settings, indexes, build artifacts and optional API use.
 - `EXPORTFORMAT.md`: planned redacted workspace export contract.
-- `web_companion/`: static read-only PWA viewer for redacted `devcenter-workspace-v1.json` exports.
 - `.github/workflows/tests.yml`: Windows smoke tests for Python 3.10, 3.11 and 3.12.
 - `src/core/app_paths.py`: XDG-compliant platform path resolver for settings and file index.