update bitcoin to 0.18.1

.editorconfig

@@ -0,0 +1,26 @@
+# This is the top-most EditorConfig file.
+root = true
+
+# For all files.
+[*]
+charset = utf-8
+end_of_line = lf
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+# Source code files
+[*.{h,cpp,rs,py,sh}]
+indent_size = 4
+
+# .cirrus.yml, etc.
+[*.yml]
+indent_size = 2
+
+# Makefiles (only relevant for depends build)
+[Makefile]
+indent_style = tab
+
+# CMake files
+[{CMakeLists.txt,*.cmake,*.cmake.in}]
+indent_size = 2

.github/ISSUE_TEMPLATE/bug.yml

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+name: Bug report
+description: Submit a new bug report.
+labels: [bug]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## This issue tracker is only for technical issues related to Bitcoin Core.
+
+        * General bitcoin questions and/or support requests should use Bitcoin StackExchange at https://bitcoin.stackexchange.com.
+        * For reporting security issues, please read instructions at https://bitcoincore.org/en/contact/.
+        * If the node is "stuck" during sync or giving "block checksum mismatch" errors, please ensure your hardware is stable by running `memtest` and observe CPU temperature with a load-test tool such as `linpack` before creating an issue.
+
+        ----
+  - type: checkboxes
+    attributes:
+      label: Is there an existing issue for this?
+      description: Please search to see if an issue already exists for the bug you encountered.
+      options:
+      - label: I have searched the existing issues
+        required: true
+  - type: textarea
+    id: current-behaviour
+    attributes:
+      label: Current behaviour
+      description: Tell us what went wrong
+    validations:
+      required: true
+  - type: textarea
+    id: expected-behaviour
+    attributes:
+      label: Expected behaviour
+      description: Tell us what you expected to happen
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction-steps
+    attributes:
+      label: Steps to reproduce
+      description: |
+        Tell us how to reproduce your bug. Please attach related screenshots if necessary.
+        * Run-time or compile-time configuration options
+        * Actions taken
+    validations:
+      required: true
+  - type: textarea
+    id: logs
+    attributes:
+      label: Relevant log output
+      description: |
+        Please copy and paste any relevant log output or attach a debug log file.
+
+        You can find the debug.log in your [data dir.](https://github.com/bitcoin/bitcoin/blob/master/doc/files.md#data-directory-location)
+
+        Please be aware that the debug log might contain personally identifying information.
+    validations:
+      required: false
+  - type: dropdown
+    attributes:
+      label: How did you obtain Bitcoin Core
+      multiple: false
+      options:
+        - Compiled from source
+        - Pre-built binaries
+        - Package manager
+        - Other
+    validations:
+      required: true
+  - type: input
+    id: core-version
+    attributes:
+      label: What version of Bitcoin Core are you using?
+      description: Run `bitcoind --version` or in Bitcoin-QT use `Help > About Bitcoin Core`
+      placeholder: e.g. v24.0.1 or master@e1bf547
+    validations:
+      required: true
+  - type: input
+    id: os
+    attributes:
+      label: Operating system and version
+      placeholder: e.g. "MacOS 26.0" or "Ubuntu 26.04 LTS"
+    validations:
+      required: true
+  - type: textarea
+    id: machine-specs
+    attributes:
+      label: Machine specifications
+      description: |
+        What are the specifications of the host machine?
+        e.g. OS/CPU and disk type, network connectivity
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/config.yml

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+blank_issues_enabled: true
+contact_links:
+  - name: Bitcoin Core Security Policy
+    url: https://github.com/bitcoin/bitcoin/blob/master/SECURITY.md
+    about: View security policy
+  - name: Bitcoin Core Developers
+    url: https://bitcoincore.org
+    about: Bitcoin Core homepage

.github/ISSUE_TEMPLATE/feature_request.yml

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+name: Feature Request
+description: Suggest an idea for this project.
+labels: [Feature]
+body:
+  - type: textarea
+    id: feature
+    attributes:
+      label: Please describe the feature you'd like to see added.
+      description: Attach screenshots or logs if applicable.
+    validations:
+      required: true
+  - type: textarea
+    id: related-problem
+    attributes:
+      label: Is your feature related to a problem, if so please describe it.
+      description: Attach screenshots or logs if applicable.
+    validations:
+      required: false
+  - type: textarea
+    id: solution
+    attributes:
+      label: Describe the solution you'd like
+    validations:
+      required: false
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Describe any alternatives you've considered
+    validations:
+      required: false
+  - type: textarea
+    id: additional-context
+    attributes:
+      label: Please leave any additional context
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/good_first_issue.yml

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+name: Good First Issue
+description: (Regular devs only) Suggest a new good first issue
+labels: [good first issue]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Please add the label "good first issue" manually before or after opening
+
+        A good first issue is an uncontroversial issue, that has a relatively unique and obvious solution
+
+        Motivate the issue and explain the solution briefly
+  - type: textarea
+    id: motivation
+    attributes:
+      label: Motivation
+      description: Motivate the issue
+    validations:
+      required: true
+  - type: textarea
+    id: solution
+    attributes:
+      label: Possible solution
+      description: Describe a possible solution
+    validations:
+      required: false
+  - type: textarea
+    id: useful-skills
+    attributes:
+      label: Useful Skills
+      description: For example, “`std::thread`”, “Qt6 GUI and async GUI design” or “basic understanding of Bitcoin mining and the Bitcoin Core RPC interface”.
+      value: |
+        * Compiling Bitcoin Core from source
+        * Running the C++ unit tests and the Python functional tests
+        * ...
+  - type: textarea
+    attributes:
+      label: Guidance for new contributors
+      description: Please leave this to automatically add the footer for new contributors
+      value: |
+        Want to work on this issue?
+
+        For guidance on contributing, please read [CONTRIBUTING.md](https://github.com/bitcoin/bitcoin/blob/master/CONTRIBUTING.md) before opening your pull request.
+

.github/ISSUE_TEMPLATE/gui_issue.yml

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+name: Issue or feature request related to the GUI
+description: Any report, issue or feature request related to the GUI
+labels: [GUI]
+body:
+- type: checkboxes
+  id: acknowledgement
+  attributes:
+    label: Issues, reports or feature requests related to the GUI should be opened directly on the GUI repo
+    description: https://github.com/bitcoin-core/gui/issues/
+    options:
+      - label: I still think this issue should be opened here
+        required: true
+- type: textarea
+  id: gui-request
+  attributes:
+    label: Report
+  validations:
+    required: true

.github/PULL_REQUEST_TEMPLATE.md

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+<!--
+*** Please remove the following help text before submitting: ***
+
+Pull requests without a rationale and clear improvement may be closed
+immediately.
+
+GUI-related pull requests should be opened against
+https://github.com/bitcoin-core/gui
+first. See CONTRIBUTING.md
+-->
+
+<!--
+Please provide clear motivation for your patch and explain how it improves
+Bitcoin Core user experience or Bitcoin Core developer experience
+significantly:
+
+* Any test improvements or new tests that improve coverage are always welcome.
+* All other changes should have accompanying unit tests (see `src/test/`) or
+  functional tests (see `test/`). Contributors should note which tests cover
+  modified code. If no tests exist for a region of modified code, new tests
+  should accompany the change.
+* Bug fixes are most welcome when they come with steps to reproduce or an
+  explanation of the potential issue as well as reasoning for the way the bug
+  was fixed.
+* Features are welcome, but might be rejected due to design or scope issues.
+  If a feature is based on a lot of dependencies, contributors should first
+  consider building the system outside of Bitcoin Core, if possible.
+* Refactoring changes are only accepted if they are required for a feature or
+  bug fix or otherwise improve developer experience significantly. For example,
+  most "code style" refactoring changes require a thorough explanation why they
+  are useful, what downsides they have and why they *significantly* improve
+  developer experience or avoid serious programming bugs. Note that code style
+  is often a subjective matter. Unless they are explicitly mentioned to be
+  preferred in the [developer notes](/doc/developer-notes.md), stylistic code
+  changes are usually rejected.
+-->
+
+<!--
+Bitcoin Core has a thorough review process and even the most trivial change
+needs to pass a lot of eyes and requires non-zero or even substantial time
+effort to review. There is a huge lack of active reviewers on the project, so
+patches often sit for a long time.
+-->

.github/actions/clear-files/action.yml

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+name: 'Clear unnecessary files'
+description: 'Clear out unnecessary files to make space on the VM'
+runs:
+  using: 'composite'
+  steps:
+    - name: Clear unnecessary files
+      shell: bash
+      env:
+        DEBIAN_FRONTEND: noninteractive
+      run: |
+        set +o errexit
+        sudo bash -c '(ionice -c 3 nice -n 19 rm -rf /usr/share/dotnet/ /usr/local/graalvm/ /usr/local/.ghcup/ /usr/local/share/powershell /usr/local/share/chromium /usr/local/lib/android /usr/local/lib/node_modules)&'

.github/actions/configure-docker/action.yml

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+name: 'Configure Docker'
+description: 'Set up Docker build driver and configure build cache args'
+inputs:
+  cache-provider:
+    description: 'gha or cirrus cache provider'
+    required: true
+runs:
+  using: 'composite'
+  steps:
+    - name: Check inputs
+      shell: python
+      run: |
+        # We expect only gha or cirrus as inputs to cache-provider
+        if "${{ inputs.cache-provider }}" not in ("gha", "cirrus"):
+          print("::warning title=Unknown input to configure docker action::Provided value was ${{ inputs.cache-provider }}")
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+      with:
+        # Use host network to allow access to cirrus gha cache running on the host
+        driver-opts: |
+          network=host
+
+    # This is required to allow buildkit to access the actions cache
+    - name: Expose actions cache variables
+      uses: actions/github-script@v6
+      with:
+        script: |
+          Object.keys(process.env).forEach(function (key) {
+            if (key.startsWith('ACTIONS_')) {
+              core.info(`Exporting ${key}`);
+              core.exportVariable(key, process.env[key]);
+            }
+          });
+
+    - name: Construct docker build cache args
+      shell: bash
+      run: |
+        # Configure docker build cache backend
+        #
+        # On forks the gha cache will work but will use Github's cache backend.
+        # Docker will check for variables $ACTIONS_CACHE_URL, $ACTIONS_RESULTS_URL and $ACTIONS_RUNTIME_TOKEN
+        # which are set automatically when running on GitHub infra: https://docs.docker.com/build/cache/backends/gha/#synopsis
+
+        # Use cirrus cache host
+        if [[ ${{ inputs.cache-provider }} == 'cirrus' ]]; then
+          url_args="url=${CIRRUS_CACHE_HOST},url_v2=${CIRRUS_CACHE_HOST}"
+        else
+          url_args=""
+        fi
+
+        # Always optimistically --cache‑from in case a cache blob exists
+        args=(--cache-from "type=gha${url_args:+,${url_args}},scope=${CONTAINER_NAME}")
+
+        # Only add --cache-to when using the Cirrus cache provider and pushing to the default branch.
+        if [[ ${{ inputs.cache-provider }} == 'cirrus' && ${{ github.event_name }} == "push" && ${{ github.ref_name }} == ${{ github.event.repository.default_branch }} ]]; then
+          args+=(--cache-to "type=gha${url_args:+,${url_args}},mode=max,ignore-error=true,scope=${CONTAINER_NAME}")
+        fi
+
+        # Always `--load` into docker images (needed when using the `docker-container` build driver).
+        args+=(--load)
+
+        echo "DOCKER_BUILD_CACHE_ARG=${args[*]}" >> $GITHUB_ENV