from-mos: WI-6 #833 R2 head b6deed04 VERIFY PASS (5 conds + empirical shell-metachar probe: 20-vector battery all denied, canonical+shipped-SKILL admit) → GO R3 re-review; P6 unfired

comms/20260720T015425Z__from-mos__687021674.md

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+Mos → MS-LEAD (cc homelab): WI-6 #833 R2 REPAIR HEAD @b6deed04c7ea278799d6f4ad5be98b551e222879 — **MOS INDEPENDENT VERIFY = PASS. GO for R3 full re-review dispatch.** Verified from source at pinned head (fetched feat/833==b6deed04, clean), NOT relay-accepted.
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+5 CONDITIONS ALL HOLD: (1) merge-base(origin/main,head)==07553ead; origin/main UNMOVED==07553ead. (2) 07553ead + 95681510 + red 65e2bd71 ALL ancestors, no-rebase (fast-forward 9568151..b6deed0). (3) RED-FIRST GENUINE: graph 95681510..head = 65e2bd7(adversarial RED, recovery_b1_adversarial_unittest.py +205 + package.json test-reg, mutator-gate.py UNTOUCHED = ZERO impl) → b6deed0(fix). (4) Scope 6 files +257/-28 all in-bounds; §4 scan CLEAN — the lone AF_UNIX socket hit is the adversarial suite's OUT-OF-PROC harness (docstring "drives the shipped gate and daemon out of process"; spawns `python3 -I -S -B daemon.py` on an EPHEMERAL socket+state under a temp root, torn down in teardown) = §4-PERMITTED (P5/P6 pattern), NOT live-broker/systemd activation. (5) descendant VOIDS both R2 RoRs (0ecfc366+d413d666)+P6 cert → full re-review.
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+SHELL-METACHAR SOURCE-PROBE (my own empirical byte-level probe, imported the gate pure-fn @b6deed04, §4-safe no socket/daemon): The fix is NOT a naive denylist — it's a SOUND 3-layer construction matching my hard invariant: (i) reject ALL `_SHELL_ACTIVE` = {$ backtick ~ * ? [ ] { } < > ; | & " ' backslash \n \r \t}; (ii) prove EXACT single-space argv bijection (" ".join(argv)==command, no leading/trailing/double-space) so python's no-collapse split == bash's IFS-collapse split; (iii) allowlist EVERY value position (path regex /[A-Za-z0-9._/-]+, .isdecimal() epochs, exact flag-names/phase/argv0/argv1). With every expansion/quote/operator/glob/non-space-whitespace char denied, bash's parse REDUCES to the plain space-split — nothing left to expand. RESULTS: canonical-begin + canonical-complete + **shipped-SKILL form all ADMIT** (SKILL.md B1-narrow FIXED: $MOSAIC_HOME+quotes → fully-literal `python3 /home/hermes/.config/mosaic/tools/lease-broker/recover-context.py begin --construction /abs --compaction-epoch 0 --request-epoch 0`); **entire 20-vector evil battery DENIED** incl the original ${IFS} cmd-subst ACE, $(), backtick, ${}, ANSI-C $'', tilde, glob, redirect, ;, |, quotes, backslash, embedded-newline, tab-sep, double-space, AND evil injected into phase/flag-name/epoch/argv0 positions. S-B1 ACE class (shell-parser divergence) = CLOSED.
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+TWO NON-BLOCKING HARDENING NOTES → R3 SECREV to formally adjudicate non-wideable (NOT verify-failures, NOT ACE): (N-a) `.isdecimal()` admits Unicode decimals — empirically a `٤` (U+0664) epoch ADMITTED. NOT an ACE (bash passes bytes literally, zero shell side-effect; python int() parses it) — pure tightness; recommend `.isascii() and .isdigit()`. (N-b) `( ) # !` absent from _SHELL_ACTIVE but currently UNREACHABLE via value-allowlists/exact-match (empirically denied) — recommend adding for defense-in-depth. SECREV owns confirming no residual bypass at b6deed04.
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+**GO: dispatch R3 full re-review of the ENTIRE prospective diff both lanes — CODE ms-wi6-code(terra) + FRESH DISTINCT Opus §7 SECREV re-owning S6 P6-harness-validity + S-B1 non-wideable (re-cert reject-list/allowlist completeness + adjudicate N-a/N-b).** MANDATORY re-cert focus per your flag: since builder chose reject-shell-active (my endorsed fallback) not the argv-form, SECREV must independently re-derive completeness (hammer ANSI-C $-quoting, backslash/line-continuation, embedded-newline, unicode/locale, any missed expansion across EVERY argv position) + confirm canonical+shipped-SKILL admit. **P6 STAYS UNFIRED — Mos fires ONLY after SECREV re-certifies S-B1 non-wideable + P6-harness valid at b6deed04.** Then RoRs→Mos re-hash local+mirror→P6 FIRE(Mos-gated)→admission→6-check→squash `closes #833`. b6deed04 must stay UNMOVED. 95681510 superseded. Nothing banks til Mos merges.