refactor(sync): put every Skill Sync verb under hermes sync; drop HSP naming

Encapsulates the feature behind one command for launch, and adopts the
official product name.

One command:
- `propose` moves from `hermes skills propose` to `hermes sync propose`, so
  the whole feature is one command to learn and one to document. Its handler
  moves from cmd_skills to cmd_sync accordingly.
- The `hermes sync` parser now documents both halves plainly: personal sync
  across your devices, and sharing with your organisation. Added an examples
  epilog; rewrote the verb help in user language ("Include a skill in your
  sync" rather than "Opt a skill into sync").
- Every user-facing string that pointed at `hermes skills propose` now points
  at `hermes sync propose` (8 sites, including the agent-visible guidance
  returned by skill_manage and the org provenance header).

This also clears the way for #39343, which adds its own top-level `sync` for
git-repo profile backup — that feature nests under `skills`, this one owns
`sync`.

Naming:
- HSP / "Hermes Sync Protocol" is gone from prose, docstrings, and comments.
  The feature is "Skill Sync".
- Public identifiers renamed: HSPClient -> SyncClient, HSPError -> SyncError,
  HSPConflict -> SyncConflict, hsp_address -> wire_address, HSP_VERSION ->
  WIRE_VERSION.
- The WIRE names are deliberately NOT renamed: the `hsp_version` capability
  field and the `x-hsp-object-type` response header are set by the deployed
  gateway-gateway sync plane (verified in src/sync/syncRouter.ts), so
  renaming them client-side would break sync against a live server. A comment
  at the version constant records why they differ from the product name.
- The version-mismatch error is now actionable ("this server speaks sync
  version X, but this Hermes speaks Y — update Hermes to sync with it")
  instead of leaking the protocol acronym.

Also fixes a wiring gap found on the way: the gateway housekeeping tick
pulled personal skills but never org skills — the same defect already fixed
for the CLI. Org pull now runs there too, gated on real org membership.

Tests: the jargon guard now also fails on a bare "HSP". The two tests that
asserted the old cross-command structure are replaced by three asserting the
new one (propose IS under sync, propose is NOT under skills, sync usage
lists it). 2294 passed / 0 failed across all 51 suites that import the
changed modules, via scripts/run_tests.sh.

Verified by running the real CLI: `hermes sync --help` lists all eight verbs,
`hermes skills --help` no longer mentions propose, `hermes sync propose
--help` parses, and `hermes sync status` still reports live org state.

tests/agent/test_org_skill_namespace.py

@@ -261,7 +261,9 @@ class TestOrgPullIsWiredIn:
             root / "hermes_cli" / "subcommands" / "sync.py",
             root / "hermes_cli" / "subcommands" / "skills.py",
         ]
-        banned = re.compile(r"\(M[12]\)|HSP/1|§[0-9]|DEV-PHASE|hsp-1-contract")
+        banned = re.compile(
+            r"\(M[12]\)|\bHSP\b|HSP/1|§[0-9]|DEV-PHASE|hsp-1-contract"
+        )
         for path in targets:
             for i, line in enumerate(path.read_text(encoding="utf-8").split("\n"), 1):
                 if "help=" in line or "description=" in line:
@@ -270,41 +272,41 @@ class TestOrgPullIsWiredIn:
                     )
 
 
-class TestOrgSharingIsDiscoverable:
-    """`hermes sync` must point users at the org-sharing command.
+class TestSkillSyncIsOneCommand:
+    """Every Skill Sync verb lives under `hermes sync` for launch.
 
-    Without this, there is no path from "I want to share this with my team"
-    to `hermes skills propose` — sync looks like the only sharing surface
-    while being personal-only.
+    The surface is deliberately encapsulated: one command to learn, one to
+    document, and top-level `sync` stays free of skill-management verbs that
+    belong elsewhere. `propose` in particular used to sit under `hermes
+    skills`, which split one feature across two commands.
     """
 
-    def test_sync_usage_block_mentions_propose(self):
+    def _src(self, *parts):
         import pathlib
 
-        main_src = (
-            pathlib.Path(__file__).resolve().parents[2]
-            / "hermes_cli"
-            / "main.py"
+        return (
+            pathlib.Path(__file__).resolve().parents[2].joinpath(*parts)
         ).read_text(encoding="utf-8")
-        usage_start = main_src.index(
-            "usage: hermes sync <status|pull|push|now|enable|disable|device>"
-        )
-        usage_block = main_src[usage_start : usage_start + 1200]
-        assert "hermes skills propose" in usage_block, (
-            "`hermes sync` usage must point at the org-sharing command."
+
+    def test_propose_is_a_sync_subcommand(self):
+        sync_src = self._src("hermes_cli", "subcommands", "sync.py")
+        assert '"propose"' in sync_src, (
+            "`propose` must be a `hermes sync` subcommand."
         )
 
-    def test_sync_parser_epilog_mentions_propose(self):
-        import pathlib
+    def test_propose_is_not_under_skills(self):
+        skills_src = self._src("hermes_cli", "subcommands", "skills.py")
+        assert '"propose"' not in skills_src, (
+            "`propose` must NOT remain under `hermes skills` — Skill Sync is "
+            "one command for launch."
+        )
 
-        src = (
-            pathlib.Path(__file__).resolve().parents[2]
-            / "hermes_cli"
-            / "subcommands"
-            / "sync.py"
-        ).read_text(encoding="utf-8")
-        assert "hermes skills propose" in src, (
-            "`hermes sync --help` must point at the org-sharing command."
+    def test_sync_usage_lists_propose(self):
+        main_src = self._src("hermes_cli", "main.py")
+        usage_start = main_src.index("usage: hermes sync ")
+        usage_block = main_src[usage_start : usage_start + 1400]
+        assert "propose" in usage_block, (
+            "`hermes sync` usage must list the propose verb."
         )