fix(licence): align everything to MPL-2.0 (Licence-consistency CI green)

[hyperpolymath]

Summary

• Standards check-licence-consistency.sh was failing on every PR (e.g. chore(deps): bump github/codeql-action from 4.34.0 to 4.36.0 in the actions group #22 run 26561538141) with [ERROR] SPDX-vs-manifest mismatch: header='MPL-2.0' manifest='PMPL-1.0-or-later'.
• LICENSE is the MPL-2.0 body and the LICENSE-file SPDX header is MPL-2.0, but 39 satellite files declared PMPL-1.0-or-later (Palimpsest), so the cross-check fired on julia-professional-registry-tests.ipkg.
• This PR resolves the inconsistency in favour of MPL-2.0 (per owner directive: human-visible, SPDX, and anywhere else).

What changed

• SPDX headers in 36 files (workflows, .a2ml manifests, docs, .ipkg, .just, .scm, etc.): PMPL-1.0-or-later → MPL-2.0.
• Manifest licence fields: stapeln.toml, .machine_readable/6a2/META.a2ml license = "PMPL-1.0-or-later" → "MPL-2.0".
• README badge (README.adoc:9): License-PMPL--1.0 shields badge + palimpsest-license link → License-MPL--2.0 + https://www.mozilla.org/en-US/MPL/2.0/.
• Human-visible: GOVERNANCE.adoc, TOPOLOGY.md, CONTRIBUTING.md, llm-warmup-{dev,user}.md, 0-AI-MANIFEST.a2ml, EXPLAINME.adoc, .github/copilot-instructions.md, contractiles/intend/Intentfile.a2ml.
• guix.scm: dropped palimpsest-license URL, now points at mozilla.org MPL/2.0.
• flake.nix: replaced stale licenses.mit ; # MIT + Palimpsest with licenses.mpl20 ; # MPL-2.0.
• Trust-content greps (contractile.just, contractiles/trust/Trustfile.a2ml): removed PMPL alternative from grep -q 'SPDX\|License\|MIT\|Apache\|PMPL\|MPL' LICENSE (no functional change — MPL still matches).
• 40 files, +54/-54, all single-token swaps. No semantic content changes.

Verification

Ran the same script the CI runs:

$ bash standards/scripts/check-licence-consistency.sh .
[OK] LICENSE file found: LICENSE
[OK] SPDX header: MPL-2.0
[OK] Manifest licence (./julia-professional-registry-tests.ipkg): MPL-2.0
[OK] SPDX header matches manifest declaration.
[OK] LICENSE body text matches SPDX header.
[OK] Licence consistency check passed.

Test plan

• bash standards/scripts/check-licence-consistency.sh . passes locally
• governance / Licence consistency CI check green on this PR
• All other governance CI checks still green (no SPDX-header-format regressions)

🤖 Generated with Claude Code