chore: officially migrate to submodule (#4502)

* remove apps/core and apps/fern

* fix precommit

* add submodule updates in workflows

* submodule

* remove core tests

* update core revision

* Add submodules: true to all GitHub workflows

- Ensure all workflows can access git submodules
- Add submodules support to deployment, test, and CI workflows
- Fix YAML syntax issues in workflow files

🤖 Generated with [Claude Code](https://claude.ai/code)

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

* remove core-lint

* upgrade core with latest main of oss

---------

Co-authored-by: Claude <noreply@anthropic.com>

Dockerfile

@@ -1,90 +0,0 @@
-# Start with pgvector base for builder
-FROM ankane/pgvector:v0.5.1 AS builder
-
-# Install Python and required packages
-RUN apt-get update && apt-get install -y \
-    python3 \
-    python3-venv \
-    python3-full \
-    build-essential \
-    libpq-dev \
-    python3-dev \
-    && rm -rf /var/lib/apt/lists/*
-
-ARG LETTA_ENVIRONMENT=DEV
-ENV LETTA_ENVIRONMENT=${LETTA_ENVIRONMENT} \
-    UV_NO_PROGRESS=1 \
-    UV_PYTHON_PREFERENCE=system \
-    UV_CACHE_DIR=/tmp/uv_cache
-
-# Set for other builds
-ARG LETTA_VERSION
-ENV LETTA_VERSION=${LETTA_VERSION}
-
-WORKDIR /app
-
-# Create and activate virtual environment
-RUN python3 -m venv /opt/venv
-ENV PATH="/opt/venv/bin:$PATH"
-
-# Now install uv and uvx in the virtual environment
-COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /usr/local/bin/
-
-
-# Copy dependency files first
-COPY pyproject.toml uv.lock ./
-# Then copy the rest of the application code
-COPY . .
-
-# TODO: strip this out into more selective dependency installation
-RUN uv sync --frozen --no-dev --all-extras --python 3.11
-
-# Runtime stage
-FROM ankane/pgvector:v0.5.1 AS runtime
-
-# Overridable Node.js version with --build-arg NODE_VERSION
-ARG NODE_VERSION=22
-
-RUN apt-get update && \
-    # Install curl, Python, and PostgreSQL client libraries
-    apt-get install -y curl python3 python3-venv libpq-dev && \
-    # Install Node.js
-    curl -fsSL https://deb.nodesource.com/setup_${NODE_VERSION}.x | bash - && \
-    apt-get install -y nodejs && \
-    # Install OpenTelemetry Collector
-    curl -L https://github.com/open-telemetry/opentelemetry-collector-releases/releases/download/v0.96.0/otelcol-contrib_0.96.0_linux_amd64.tar.gz -o /tmp/otel-collector.tar.gz && \
-    tar xzf /tmp/otel-collector.tar.gz -C /usr/local/bin && \
-    rm /tmp/otel-collector.tar.gz && \
-    mkdir -p /etc/otel && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/*
-
-# Add OpenTelemetry Collector configs
-COPY otel/otel-collector-config-file.yaml /etc/otel/config-file.yaml
-COPY otel/otel-collector-config-clickhouse.yaml /etc/otel/config-clickhouse.yaml
-COPY otel/otel-collector-config-signoz.yaml /etc/otel/config-signoz.yaml
-
-ARG LETTA_ENVIRONMENT=DEV
-ENV LETTA_ENVIRONMENT=${LETTA_ENVIRONMENT} \
-    VIRTUAL_ENV="/app/.venv" \
-    PATH="/app/.venv/bin:$PATH" \
-    POSTGRES_USER=letta \
-    POSTGRES_PASSWORD=letta \
-    POSTGRES_DB=letta \
-    COMPOSIO_DISABLE_VERSION_CHECK=true
-
-ARG LETTA_VERSION
-ENV LETTA_VERSION=${LETTA_VERSION}
-
-WORKDIR /app
-
-# Copy virtual environment and app from builder
-COPY --from=builder /app .
-
-# Copy initialization SQL if it exists
-COPY init.sql /docker-entrypoint-initdb.d/
-
-EXPOSE 8283 5432 4317 4318
-
-ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
-CMD ["./letta/server/startup.sh"]