fix(installer): memory truth — machine RAM vs Docker's budget, advice clamped to the machine (Windows half of #417)

[LukasWodka]

Summary

Windows half of #417. Three memory-reporting bugs seen live across all three test environments (7 GB / 6 GB / 15 GB readings, and a 15 GB laptop told to "give Docker ≥ 16 GB"):

1. Flip-flop: the "Memory:" line preferred docker info MemTotal (the WSL2 VM's 50%-of-RAM default) over physical RAM — same machine, different numbers across re-runs depending on whether Docker happened to be up.
2. Impossible advice: recommendations used the raw 16 GB constant regardless of what the machine has.
3. Diverging copy: Step 1 and the Step-2 post-Docker re-check printed different warnings for the same condition, and could both fire in one run.

Change

• Get-PfHostMemGb (CIM only) replaces the runtime-preferring Get-PfMemGb. Step 1 prints two labeled truths: Memory: 15 GB (machine) always, and Docker's memory budget: 7 GB … when a runtime is up.
• Get-PfMemTargets clamps Docker-budget advice to host − 2 GB (floor 4) → the 15 GB laptop now gets [wsl2] memory=13GB. Hardware statements ("16 GB of RAM recommended to train") stay unclamped — they describe the machine, not a setting.
• Write-PfRuntimeMemStatus is the single shared copy for the budget line (Step 1 + Step 2), with a latch so one run warns once.
• Tests: clamp matrix (15/8/32/unknown GB hosts), two-line integration assertion, Step-2 dedupe latch, existing preflight tests rewired to the new readers; the old "prefers docker MemTotal" test is deleted — that preference was the bug.
• manifest.sha256 regenerated.

Out of scope, noted: Get-PfCpu still prefers the runtime view (same class, milder — cores don't halve); macOS floor enforcement + VM sizing is #428; the bash half of this ticket follows separately (same labels + clamp in preflight.sh).

Stacked on #440 → #439 → #438 → #437 — merge in that order; this branch contains all of them.

Type

Bug fix

Test plan

Full Pester suite locally on pwsh 7.5 (CI invocation): 181 passed, 0 failed, 8 skipped (9 new). gen-manifest.sh --check clean.

🤖 Generated with Claude Code

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Note

Low Risk
Installer preflight messaging and warn-only memory checks only; no cluster, auth, or data-path changes.

Overview
Fixes Windows installer memory reporting (#417) so preflight no longer mixes up physical RAM with Docker/WSL2's VM budget.

Get-PfHostMemGb (CIM-only) replaces the old runtime-preferring reader. Step 1 always prints Memory: N GB (machine); when Docker is already running it adds a second line for Docker's memory budget via Write-PfRuntimeMemStatus.

Get-PfMemTargets clamps Docker-setting hints to host − 2 GB (floor 4), so a 15 GB laptop gets memory=13GB in .wslconfig instead of impossible "give Docker ≥ 16 GB". Training RAM recommendations for the machine itself stay at the full defaults.

Test-PreflightRuntimeMem reuses the same budget copy and $script:RuntimeMemWarned so Step 1 and the post-Docker re-check don't double-warn in one run.

Pester coverage adds clamp matrices, two-line preflight assertions, and latch behavior; scripts/manifest.sha256 is updated for install-k8s.ps1.

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[LukasWodka]

bugbot run

[LukasWodka]

Converted to draft to disable the merge button while the base is a feature branch (the #438-#440 mis-merge trap). Plan: once #447 (re-land of #412/#413) merges to develop, rebase this onto develop, retarget, regen manifest.sha256, re-run Pester, flip ready.

[LukasWodka]

Rebased onto develop as a single clean commit (the tangled pre-squash history and the duplicate #440 copy-fix are gone — develop already carries that content byte-identically via #447). Manifest regenerated; full Pester green locally. bugbot run

[LukasWodka]

bugbot run

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[LukasWodka]

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