You are correct about the Claisen condensation and the decarboxylation. You can't solve the synthesis as shown because there are too many steps. Ethyl nicotinate (**1**) and the lactam **2** condense to form the sodium salt of **3** in a reaction stoichiometric in base. That is to say, the reaction is not catalytic in base. Vigorous treatment with aq. HCl will neutralize the sodium salt **3**, hydrolyse the lactam, and effect decarboxylation of the intermediate &beta;-ketoester forming the salt **4**. In my experience in a related case, neutralization of the salt with aqueous alkali, extraction with ether, and drying the extract over anhydrous $\ce{MgSO4}$ will afford dehydronicotine **5** via enamine formation. Hydrogen produces racemic nicotine **6**. The last two steps of the scheme are unnecessary. This said, I believe the scheme is made up. See the reference below and citations therein.<br>

1) C. J. Dunsmore, R. Carr, T. Fleming, and N. J. Turner, [*J. Am. Chem. Soc.*, **2006**, *128*, 2224.][1]

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  [1]: https://pubs.acs.org/doi/10.1021/ja058536d